diff --git a/src/clang_complete.cc b/src/clang_complete.cc
index c8419b5f..9566ebb5 100644
--- a/src/clang_complete.cc
+++ b/src/clang_complete.cc
@@ -6,8 +6,8 @@
 #include "clang_tu.hh"
 #include "filesystem.hh"
 #include "log.hh"
-#include "match.h"
-#include "platform.h"
+#include "match.hh"
+#include "platform.hh"
 
 #include <clang/Lex/PreprocessorOptions.h>
 #include <clang/Sema/CodeCompleteConsumer.h>
@@ -406,7 +406,7 @@ void *CompletionMain(void *manager_) {
 
     DiagnosticConsumer DC;
     WorkingFiles::Snapshot snapshot =
-      manager->working_files_->AsSnapshot({StripFileType(path)});
+      manager->wfiles_->AsSnapshot({StripFileType(path)});
     std::vector<std::unique_ptr<llvm::MemoryBuffer>> Bufs;
     auto Clang = BuildCompilerInstance(*session, std::move(CI), FS, DC,
                                        preamble.get(), snapshot, Bufs);
@@ -480,7 +480,7 @@ void *DiagnosticMain(void *manager_) {
     CI->getLangOpts()->SpellChecking = g_config->diagnostics.spellChecking;
     StoreDiags DC(path);
     WorkingFiles::Snapshot snapshot =
-        manager->working_files_->AsSnapshot({StripFileType(path)});
+        manager->wfiles_->AsSnapshot({StripFileType(path)});
     std::vector<std::unique_ptr<llvm::MemoryBuffer>> Bufs;
     auto Clang = BuildCompilerInstance(*session, std::move(CI), FS, DC,
                                        preamble.get(), snapshot, Bufs);
@@ -564,10 +564,10 @@ std::shared_ptr<PreambleData> CompletionSession::GetPreamble() {
 }
 
 CompletionManager::CompletionManager(Project *project,
-                                     WorkingFiles *working_files,
+                                     WorkingFiles *wfiles,
                                      OnDiagnostic on_diagnostic,
                                      OnDropped on_dropped)
-    : project_(project), working_files_(working_files),
+    : project_(project), wfiles_(wfiles),
       on_diagnostic_(on_diagnostic), on_dropped_(on_dropped),
       preloads(kMaxPreloadedSessions),
       sessions(kMaxCompletionSessions),
@@ -626,7 +626,7 @@ bool CompletionManager::EnsureCompletionOrCreatePreloadSession(
 
   // No CompletionSession, create new one.
   auto session = std::make_shared<ccls::CompletionSession>(
-      project_->FindEntry(path, false), working_files_, PCH);
+      project_->FindEntry(path, false), wfiles_, PCH);
   if (session->file.filename != path) {
     session->inferred = true;
     session->file.filename = path;
@@ -655,7 +655,7 @@ CompletionManager::TryGetSession(const std::string &path, bool preload,
   session = sessions.TryGet(path);
   if (!session && !preload) {
     session = std::make_shared<ccls::CompletionSession>(
-        project_->FindEntry(path, false), working_files_, PCH);
+        project_->FindEntry(path, false), wfiles_, PCH);
     sessions.Insert(path, session);
     LOG_S(INFO) << "create session for " << path;
     if (is_open)
diff --git a/src/clang_complete.hh b/src/clang_complete.hh
index 21ce4876..e1984e93 100644
--- a/src/clang_complete.hh
+++ b/src/clang_complete.hh
@@ -4,11 +4,11 @@
 #pragma once
 
 #include "clang_tu.hh"
-#include "lru_cache.h"
+#include "lru_cache.hh"
 #include "lsp.hh"
 #include "project.hh"
-#include "threaded_queue.h"
-#include "working_files.h"
+#include "threaded_queue.hh"
+#include "working_files.hh"
 
 #include <clang/Frontend/CompilerInstance.h>
 #include <clang/Frontend/FrontendActions.h>
@@ -96,7 +96,7 @@ struct CompletionManager {
     int64_t debounce;
   };
 
-  CompletionManager(Project *project, WorkingFiles *working_files,
+  CompletionManager(Project *project, WorkingFiles *wfiles,
                     OnDiagnostic on_diagnostic, OnDropped on_dropped);
 
   // Request a diagnostics update.
@@ -129,7 +129,7 @@ struct CompletionManager {
 
   // Global state.
   Project *project_;
-  WorkingFiles *working_files_;
+  WorkingFiles *wfiles_;
   OnDiagnostic on_diagnostic_;
   OnDropped on_dropped_;
 
diff --git a/src/clang_tu.cc b/src/clang_tu.cc
index 2a85e694..5bacc9b8 100644
--- a/src/clang_tu.cc
+++ b/src/clang_tu.cc
@@ -3,8 +3,8 @@
 
 #include "clang_tu.hh"
 
-#include "config.h"
-#include "platform.h"
+#include "config.hh"
+#include "platform.hh"
 
 #include <clang/AST/Type.h>
 #include <clang/Lex/Lexer.h>
diff --git a/src/clang_tu.hh b/src/clang_tu.hh
index 29cda7f9..f301334f 100644
--- a/src/clang_tu.hh
+++ b/src/clang_tu.hh
@@ -3,7 +3,7 @@
 
 #pragma once
 
-#include "position.h"
+#include "position.hh"
 
 #include <clang/Basic/LangOptions.h>
 #include <clang/Basic/FileManager.h>
diff --git a/src/config.cc b/src/config.cc
index 5ba8f5c4..34284c6a 100644
--- a/src/config.cc
+++ b/src/config.cc
@@ -1,7 +1,7 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "config.h"
+#include "config.hh"
 
 namespace ccls {
 Config *g_config;
diff --git a/src/config.h b/src/config.hh
similarity index 100%
rename from src/config.h
rename to src/config.hh
diff --git a/src/filesystem.cc b/src/filesystem.cc
index ff797b0b..e85e663f 100644
--- a/src/filesystem.cc
+++ b/src/filesystem.cc
@@ -4,7 +4,7 @@
 #include "filesystem.hh"
 using namespace llvm;
 
-#include "utils.h"
+#include "utils.hh"
 
 #include <set>
 #include <vector>
diff --git a/src/fuzzy_match.cc b/src/fuzzy_match.cc
index 7c44c452..af1dd532 100644
--- a/src/fuzzy_match.cc
+++ b/src/fuzzy_match.cc
@@ -1,7 +1,7 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "fuzzy_match.h"
+#include "fuzzy_match.hh"
 
 #include <algorithm>
 #include <ctype.h>
diff --git a/src/fuzzy_match.h b/src/fuzzy_match.hh
similarity index 100%
rename from src/fuzzy_match.h
rename to src/fuzzy_match.hh
diff --git a/src/include_complete.cc b/src/include_complete.cc
index 71749012..2703d296 100644
--- a/src/include_complete.cc
+++ b/src/include_complete.cc
@@ -1,11 +1,11 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "include_complete.h"
+#include "include_complete.hh"
 
 #include "filesystem.hh"
-#include "match.h"
-#include "platform.h"
+#include "match.hh"
+#include "platform.hh"
 #include "project.hh"
 
 #include <llvm/ADT/Twine.h>
diff --git a/src/include_complete.h b/src/include_complete.hh
similarity index 100%
rename from src/include_complete.h
rename to src/include_complete.hh
diff --git a/src/indexer.cc b/src/indexer.cc
index 7bca21d6..6dc51d6b 100644
--- a/src/indexer.cc
+++ b/src/indexer.cc
@@ -1,14 +1,14 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "indexer.h"
+#include "indexer.hh"
 
 #include "clang_complete.hh"
 #include "clang_tu.hh"
 #include "log.hh"
-#include "match.h"
+#include "match.hh"
 #include "pipeline.hh"
-#include "platform.h"
+#include "platform.hh"
 #include "serializer.hh"
 
 #include <clang/AST/AST.h>
diff --git a/src/indexer.h b/src/indexer.hh
similarity index 99%
rename from src/indexer.h
rename to src/indexer.hh
index 7f353563..e60ce661 100644
--- a/src/indexer.h
+++ b/src/indexer.hh
@@ -4,10 +4,10 @@
 #pragma once
 
 #include "lsp.hh"
-#include "maybe.h"
-#include "position.h"
+#include "maybe.hh"
+#include "position.hh"
 #include "serializer.hh"
-#include "utils.h"
+#include "utils.hh"
 
 #include <clang/Basic/FileManager.h>
 #include <clang/Basic/Specifiers.h>
diff --git a/src/lru_cache.h b/src/lru_cache.hh
similarity index 100%
rename from src/lru_cache.h
rename to src/lru_cache.hh
diff --git a/src/lsp.cc b/src/lsp.cc
index 50e9d5de..324faf43 100644
--- a/src/lsp.cc
+++ b/src/lsp.cc
@@ -4,7 +4,7 @@
 #include "lsp.hh"
 
 #include "log.hh"
-#include "serializers/json.h"
+#include "serializers/json.hh"
 
 #include <algorithm>
 #include <stdio.h>
diff --git a/src/lsp.hh b/src/lsp.hh
index 9b8731ee..ae1e494a 100644
--- a/src/lsp.hh
+++ b/src/lsp.hh
@@ -3,9 +3,9 @@
 
 #pragma once
 
-#include "config.h"
+#include "config.hh"
 #include "serializer.hh"
-#include "utils.h"
+#include "utils.hh"
 
 #include <rapidjson/fwd.h>
 
diff --git a/src/main.cc b/src/main.cc
index e6521c05..d0cd9940 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -3,11 +3,11 @@
 
 #include "log.hh"
 #include "pipeline.hh"
-#include "platform.h"
+#include "platform.hh"
 #include "serializer.hh"
-#include "serializers/json.h"
-#include "test.h"
-#include "working_files.h"
+#include "serializers/json.hh"
+#include "test.hh"
+#include "working_files.hh"
 
 #include <llvm/Support/CommandLine.h>
 #include <llvm/Support/CrashRecoveryContext.h>
diff --git a/src/match.cc b/src/match.cc
index 808bc180..9d3221a6 100644
--- a/src/match.cc
+++ b/src/match.cc
@@ -1,7 +1,7 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "match.h"
+#include "match.hh"
 
 #include "lsp.hh"
 #include "pipeline.hh"
diff --git a/src/match.h b/src/match.hh
similarity index 100%
rename from src/match.h
rename to src/match.hh
diff --git a/src/maybe.h b/src/maybe.hh
similarity index 100%
rename from src/maybe.h
rename to src/maybe.hh
diff --git a/src/message_handler.cc b/src/message_handler.cc
index b860d074..7abf842f 100644
--- a/src/message_handler.cc
+++ b/src/message_handler.cc
@@ -4,11 +4,11 @@
 #include "message_handler.hh"
 
 #include "log.hh"
-#include "match.h"
+#include "match.hh"
 #include "pipeline.hh"
 #include "project.hh"
-#include "query_utils.h"
-#include "serializers/json.h"
+#include "query_utils.hh"
+#include "serializers/json.hh"
 
 using namespace clang;
 
diff --git a/src/message_handler.hh b/src/message_handler.hh
index a46ff8c3..5eb7e608 100644
--- a/src/message_handler.hh
+++ b/src/message_handler.hh
@@ -4,7 +4,7 @@
 #pragma once
 
 #include "lsp.hh"
-#include "query.h"
+#include "query.hh"
 
 #include <functional>
 #include <memory>
@@ -184,7 +184,7 @@ struct MessageHandler {
   DB *db = nullptr;
   Project *project = nullptr;
   VFS *vfs = nullptr;
-  WorkingFiles *working_files = nullptr;
+  WorkingFiles *wfiles = nullptr;
   CompletionManager *clang_complete = nullptr;
   IncludeComplete *include_complete = nullptr;
 
diff --git a/src/messages/ccls_call.cc b/src/messages/ccls_call.cc
index 46b9044e..2cb703b4 100644
--- a/src/messages/ccls_call.cc
+++ b/src/messages/ccls_call.cc
@@ -4,7 +4,7 @@
 #include "hierarchy.hh"
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 #include <unordered_set>
 
@@ -73,7 +73,7 @@ bool Expand(MessageHandler *m, Out_cclsCall *entry, bool callee,
       Out_cclsCall entry1;
       entry1.id = std::to_string(sym.usr);
       entry1.usr = sym.usr;
-      if (auto loc = GetLsLocation(m->db, m->working_files,
+      if (auto loc = GetLsLocation(m->db, m->wfiles,
                                    Use{{sym.range, sym.role}, file_id}))
         entry1.location = *loc;
       entry1.callType = call_type1;
@@ -163,7 +163,7 @@ std::optional<Out_cclsCall> BuildInitial(MessageHandler *m, Usr root_usr,
   entry.usr = root_usr;
   entry.callType = CallType::Direct;
   if (def->spell) {
-    if (auto loc = GetLsLocation(m->db, m->working_files, *def->spell))
+    if (auto loc = GetLsLocation(m->db, m->wfiles, *def->spell))
       entry.location = *loc;
   }
   Expand(m, &entry, callee, call_type, qualified, levels);
@@ -193,7 +193,7 @@ void MessageHandler::ccls_call(Reader &reader, ReplyOnce &reply) {
     if (!file)
       return;
     WorkingFile *working_file =
-        working_files->GetFileByFilename(file->def->path);
+        wfiles->GetFileByFilename(file->def->path);
     for (SymbolRef sym :
          FindSymbolsAtLocation(working_file, file, param.position)) {
       if (sym.kind == SymbolKind::Func) {
diff --git a/src/messages/ccls_info.cc b/src/messages/ccls_info.cc
index f29d2edb..119acd57 100644
--- a/src/messages/ccls_info.cc
+++ b/src/messages/ccls_info.cc
@@ -4,7 +4,7 @@
 #include "message_handler.hh"
 #include "pipeline.hh"
 #include "project.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 namespace ccls {
 MAKE_REFLECT_STRUCT(QueryFile::Def, path, args, language, skipped_ranges,
diff --git a/src/messages/ccls_inheritance.cc b/src/messages/ccls_inheritance.cc
index ae57429d..6a206edf 100644
--- a/src/messages/ccls_inheritance.cc
+++ b/src/messages/ccls_inheritance.cc
@@ -4,7 +4,7 @@
 #include "hierarchy.hh"
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 #include <unordered_set>
 
@@ -52,10 +52,10 @@ bool ExpandHelper(MessageHandler *m, Out_cclsInheritance *entry, bool derived,
   if (def) {
     entry->name = def->Name(qualified);
     if (def->spell) {
-      if (auto loc = GetLsLocation(m->db, m->working_files, *def->spell))
+      if (auto loc = GetLsLocation(m->db, m->wfiles, *def->spell))
         entry->location = *loc;
     } else if (entity.declarations.size()) {
-      if (auto loc = GetLsLocation(m->db, m->working_files, entity.declarations[0]))
+      if (auto loc = GetLsLocation(m->db, m->wfiles, entity.declarations[0]))
         entry->location = *loc;
     }
   } else if (!derived) {
@@ -138,7 +138,7 @@ void Inheritance(MessageHandler *m, Param &param, ReplyOnce &reply) {
     QueryFile *file = m->FindFile(reply, param.textDocument.uri.GetPath());
     if (!file)
       return;
-    WorkingFile *wfile = m->working_files->GetFileByFilename(file->def->path);
+    WorkingFile *wfile = m->wfiles->GetFileByFilename(file->def->path);
 
     for (SymbolRef sym : FindSymbolsAtLocation(wfile, file, param.position))
       if (sym.kind == SymbolKind::Func || sym.kind == SymbolKind::Type) {
diff --git a/src/messages/ccls_member.cc b/src/messages/ccls_member.cc
index 9c6f087d..e3d97fb4 100644
--- a/src/messages/ccls_member.cc
+++ b/src/messages/ccls_member.cc
@@ -5,7 +5,7 @@
 #include "hierarchy.hh"
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 #include <clang/AST/Type.h>
 #include <llvm/ADT/DenseSet.h>
@@ -78,7 +78,7 @@ void DoField(MessageHandler *m, Out_cclsMember *entry, const QueryVar &var,
   }
   if (def1->spell) {
     if (std::optional<lsLocation> loc =
-            GetLsLocation(m->db, m->working_files, *def1->spell))
+            GetLsLocation(m->db, m->wfiles, *def1->spell))
       entry1.location = *loc;
   }
   if (def1->type) {
@@ -133,13 +133,13 @@ bool Expand(MessageHandler *m, Out_cclsMember *entry, bool qualified,
         if (def1 && def1->spell) {
           // The declaration of target type.
           if (std::optional<lsLocation> loc =
-            GetLsLocation(m->db, m->working_files, *def1->spell))
+            GetLsLocation(m->db, m->wfiles, *def1->spell))
             entry1.location = *loc;
         } else if (def->spell) {
           // Builtin types have no declaration but the typedef declaration
           // itself is useful.
           if (std::optional<lsLocation> loc =
-            GetLsLocation(m->db, m->working_files, *def->spell))
+            GetLsLocation(m->db, m->wfiles, *def->spell))
             entry1.location = *loc;
         }
         if (def1 && qualified)
@@ -161,10 +161,10 @@ bool Expand(MessageHandler *m, Out_cclsMember *entry, bool qualified,
                 entry1.fieldName = def1->Name(false);
                 if (def1->spell) {
                   if (auto loc =
-                          GetLsLocation(m->db, m->working_files, *def1->spell))
+                          GetLsLocation(m->db, m->wfiles, *def1->spell))
                     entry1.location = *loc;
                 } else if (func1.declarations.size()) {
-                  if (auto loc = GetLsLocation(m->db, m->working_files,
+                  if (auto loc = GetLsLocation(m->db, m->wfiles,
                                                func1.declarations[0]))
                     entry1.location = *loc;
                 }
@@ -182,10 +182,10 @@ bool Expand(MessageHandler *m, Out_cclsMember *entry, bool qualified,
                 entry1.fieldName = def1->Name(false);
                 if (def1->spell) {
                   if (auto loc =
-                    GetLsLocation(m->db, m->working_files, *def1->spell))
+                    GetLsLocation(m->db, m->wfiles, *def1->spell))
                     entry1.location = *loc;
                 } else if (type1.declarations.size()) {
-                  if (auto loc = GetLsLocation(m->db, m->working_files,
+                  if (auto loc = GetLsLocation(m->db, m->wfiles,
                       type1.declarations[0]))
                     entry1.location = *loc;
                 }
@@ -224,7 +224,7 @@ std::optional<Out_cclsMember> BuildInitial(MessageHandler *m, SymbolKind kind,
     // Not type, |id| is invalid.
     entry.name = def->Name(qualified);
     if (def->spell) {
-      if (auto loc = GetLsLocation(m->db, m->working_files, *def->spell))
+      if (auto loc = GetLsLocation(m->db, m->wfiles, *def->spell))
         entry.location = *loc;
     }
     for (Usr usr : def->vars) {
@@ -243,7 +243,7 @@ std::optional<Out_cclsMember> BuildInitial(MessageHandler *m, SymbolKind kind,
     entry.id = std::to_string(root_usr);
     entry.usr = root_usr;
     if (def->spell) {
-      if (auto loc = GetLsLocation(m->db, m->working_files, *def->spell))
+      if (auto loc = GetLsLocation(m->db, m->wfiles, *def->spell))
         entry.location = *loc;
     }
     Expand(m, &entry, qualified, levels, memberKind);
@@ -274,7 +274,7 @@ void MessageHandler::ccls_member(Reader &reader, ReplyOnce &reply) {
     QueryFile *file = FindFile(reply, param.textDocument.uri.GetPath());
     if (!file)
       return;
-    WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+    WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
     for (SymbolRef sym :
          FindSymbolsAtLocation(wfile, file, param.position)) {
       switch (sym.kind) {
diff --git a/src/messages/ccls_navigate.cc b/src/messages/ccls_navigate.cc
index 7f69c380..b52d8345 100644
--- a/src/messages/ccls_navigate.cc
+++ b/src/messages/ccls_navigate.cc
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "message_handler.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 namespace ccls {
 namespace {
@@ -34,7 +34,7 @@ void MessageHandler::ccls_navigate(Reader &reader,
   if (!file)
     return;
 
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   lsPosition ls_pos = param.position;
   if (wfile && wfile->index_lines.size())
     if (auto line = wfile->GetIndexPosFromBufferPos(ls_pos.line,
diff --git a/src/messages/ccls_reload.cc b/src/messages/ccls_reload.cc
index 57c29fed..1ee03dd5 100644
--- a/src/messages/ccls_reload.cc
+++ b/src/messages/ccls_reload.cc
@@ -2,11 +2,11 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "clang_complete.hh"
-#include "match.h"
+#include "match.hh"
 #include "message_handler.hh"
 #include "pipeline.hh"
 #include "project.hh"
-#include "working_files.h"
+#include "working_files.hh"
 
 #include <queue>
 #include <unordered_set>
@@ -28,7 +28,7 @@ void MessageHandler::ccls_reload(Reader &reader) {
   if (param.whitelist.empty() && param.blacklist.empty()) {
     vfs->Clear();
     db->clear();
-    project->Index(working_files, lsRequestId());
+    project->Index(wfiles, lsRequestId());
     clang_complete->FlushAllSessions();
     return;
   }
diff --git a/src/messages/ccls_vars.cc b/src/messages/ccls_vars.cc
index edd84181..13b81752 100644
--- a/src/messages/ccls_vars.cc
+++ b/src/messages/ccls_vars.cc
@@ -3,7 +3,7 @@
 
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 namespace ccls {
 namespace {
@@ -22,7 +22,7 @@ void MessageHandler::ccls_vars(Reader &reader, ReplyOnce &reply) {
   QueryFile *file = FindFile(reply, param.textDocument.uri.GetPath());
   if (!file)
     return;
-  WorkingFile *working_file = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *working_file = wfiles->GetFileByFilename(file->def->path);
 
   std::vector<lsLocation> result;
   for (SymbolRef sym :
@@ -40,7 +40,7 @@ void MessageHandler::ccls_vars(Reader &reader, ReplyOnce &reply) {
     }
     case SymbolKind::Type:
       result = GetLsLocations(
-          db, working_files,
+          db, wfiles,
           GetVarDeclarations(db, db->Type(usr).instances, param.kind));
       break;
     }
diff --git a/src/messages/initialize.cc b/src/messages/initialize.cc
index f468120b..2e4b1fd9 100644
--- a/src/messages/initialize.cc
+++ b/src/messages/initialize.cc
@@ -3,14 +3,14 @@
 
 #include "clang_complete.hh"
 #include "filesystem.hh"
-#include "include_complete.h"
+#include "include_complete.hh"
 #include "log.hh"
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "platform.h"
+#include "platform.hh"
 #include "project.hh"
-#include "serializers/json.h"
-#include "working_files.h"
+#include "serializers/json.hh"
+#include "working_files.hh"
 
 #include <llvm/ADT/Twine.h>
 #include <llvm/Support/Threading.h>
@@ -349,7 +349,7 @@ void *Indexer(void *arg_) {
   std::string name = "indexer" + std::to_string(idx);
   set_thread_name(name.c_str());
   pipeline::Indexer_Main(h->clang_complete, h->vfs, h->project,
-                         h->working_files);
+                         h->wfiles);
   return nullptr;
 }
 } // namespace
@@ -445,7 +445,7 @@ void Initialize(MessageHandler *m, lsInitializeParams &param, ReplyOnce &reply)
   m->include_complete->Rescan();
 
   LOG_S(INFO) << "dispatch initial index requests";
-  m->project->Index(m->working_files, reply.id);
+  m->project->Index(m->wfiles, reply.id);
 }
 
 void MessageHandler::initialize(Reader &reader, ReplyOnce &reply) {
diff --git a/src/messages/textDocument_code.cc b/src/messages/textDocument_code.cc
index 0d425fd5..b96f8039 100644
--- a/src/messages/textDocument_code.cc
+++ b/src/messages/textDocument_code.cc
@@ -3,8 +3,8 @@
 
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "query_utils.h"
-#include "serializers/json.h"
+#include "query_utils.hh"
+#include "serializers/json.hh"
 
 #include <llvm/Support/FormatVariadic.h>
 
@@ -22,13 +22,13 @@ MAKE_REFLECT_STRUCT(CodeAction, title, kind, edit);
 void MessageHandler::textDocument_codeAction(CodeActionParam &param,
                                              ReplyOnce &reply) {
   WorkingFile *wfile =
-      working_files->GetFileByFilename(param.textDocument.uri.GetPath());
+      wfiles->GetFileByFilename(param.textDocument.uri.GetPath());
   if (!wfile) {
     return;
   }
   std::vector<CodeAction> result;
   std::vector<lsDiagnostic> diagnostics;
-  working_files->DoAction([&]() { diagnostics = wfile->diagnostics_; });
+  wfiles->DoAction([&]() { diagnostics = wfile->diagnostics_; });
   for (lsDiagnostic &diag : diagnostics)
     if (diag.fixits_.size()) {
       CodeAction &cmd = result.emplace_back();
@@ -83,7 +83,7 @@ void MessageHandler::textDocument_codeLens(TextDocumentParam &param,
 
   QueryFile *file = FindFile(reply, path);
   WorkingFile *wfile =
-      file ? working_files->GetFileByFilename(file->def->path) : nullptr;
+      file ? wfiles->GetFileByFilename(file->def->path) : nullptr;
   if (!wfile) {
     return;
   }
@@ -176,7 +176,7 @@ void MessageHandler::workspace_executeCommand(Reader &reader,
     std::vector<lsLocation> result;
     auto Map = [&](auto &&uses) {
       for (auto &use : uses)
-        if (auto loc = GetLsLocation(db, working_files, use))
+        if (auto loc = GetLsLocation(db, wfiles, use))
           result.push_back(std::move(*loc));
     };
     switch (cmd.kind) {
diff --git a/src/messages/textDocument_completion.cc b/src/messages/textDocument_completion.cc
index 1e510e4e..aef6c179 100644
--- a/src/messages/textDocument_completion.cc
+++ b/src/messages/textDocument_completion.cc
@@ -2,12 +2,12 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "clang_complete.hh"
-#include "fuzzy_match.h"
-#include "include_complete.h"
+#include "fuzzy_match.hh"
+#include "include_complete.hh"
 #include "log.hh"
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "working_files.h"
+#include "working_files.hh"
 
 #include <clang/Sema/CodeCompleteConsumer.h>
 #include <clang/Sema/Sema.h>
@@ -441,7 +441,7 @@ void MessageHandler::textDocument_completion(lsCompletionParams &param,
   static CompleteConsumerCache<std::vector<lsCompletionItem>> cache;
   lsCompletionList result;
   std::string path = param.textDocument.uri.GetPath();
-  WorkingFile *file = working_files->GetFileByFilename(path);
+  WorkingFile *file = wfiles->GetFileByFilename(path);
   if (!file) {
     return;
   }
diff --git a/src/messages/textDocument_definition.cc b/src/messages/textDocument_definition.cc
index 05a5407e..ed77efbf 100644
--- a/src/messages/textDocument_definition.cc
+++ b/src/messages/textDocument_definition.cc
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "message_handler.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 #include <ctype.h>
 #include <limits.h>
@@ -42,7 +42,7 @@ void MessageHandler::textDocument_definition(TextDocumentPositionParam &param,
 
   std::vector<lsLocation> result;
   Maybe<Use> on_def;
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   lsPosition &ls_pos = param.position;
 
   for (SymbolRef sym : FindSymbolsAtLocation(wfile, file, ls_pos, true)) {
@@ -75,7 +75,7 @@ void MessageHandler::textDocument_definition(TextDocumentPositionParam &param,
       if (uses.empty() && on_def)
         uses.push_back(*on_def);
     }
-    auto locs = GetLsLocations(db, working_files, uses);
+    auto locs = GetLsLocations(db, wfiles, uses);
     result.insert(result.end(), locs.begin(), locs.end());
   }
 
@@ -146,7 +146,7 @@ void MessageHandler::textDocument_definition(TextDocumentPositionParam &param,
       if (best_sym.kind != SymbolKind::Invalid) {
         Maybe<DeclRef> dr = GetDefinitionSpell(db, best_sym);
         assert(dr);
-        if (auto loc = GetLsLocation(db, working_files, *dr))
+        if (auto loc = GetLsLocation(db, wfiles, *dr))
           result.push_back(*loc);
       }
     }
@@ -160,18 +160,18 @@ void MessageHandler::textDocument_typeDefinition(
   QueryFile *file = FindFile(reply, param.textDocument.uri.GetPath());
   if (!file)
     return;
-  WorkingFile *working_file = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *working_file = wfiles->GetFileByFilename(file->def->path);
 
   std::vector<lsLocation> result;
   auto Add = [&](const QueryType &type) {
     for (const auto &def : type.def)
       if (def.spell) {
-        if (auto ls_loc = GetLsLocation(db, working_files, *def.spell))
+        if (auto ls_loc = GetLsLocation(db, wfiles, *def.spell))
           result.push_back(*ls_loc);
       }
     if (result.empty())
       for (const DeclRef &dr : type.declarations)
-        if (auto ls_loc = GetLsLocation(db, working_files, dr))
+        if (auto ls_loc = GetLsLocation(db, wfiles, dr))
           result.push_back(*ls_loc);
   };
   for (SymbolRef sym :
diff --git a/src/messages/textDocument_did.cc b/src/messages/textDocument_did.cc
index 5e02ac9f..5ef8adb4 100644
--- a/src/messages/textDocument_did.cc
+++ b/src/messages/textDocument_did.cc
@@ -2,16 +2,16 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "clang_complete.hh"
-#include "include_complete.h"
+#include "include_complete.hh"
 #include "message_handler.hh"
 #include "pipeline.hh"
 #include "project.hh"
-#include "working_files.h"
+#include "working_files.hh"
 
 namespace ccls {
 void MessageHandler::textDocument_didChange(TextDocumentDidChangeParam &param) {
   std::string path = param.textDocument.uri.GetPath();
-  working_files->OnChange(param);
+  wfiles->OnChange(param);
   if (g_config->index.onChange)
     pipeline::Index(path, {}, IndexMode::OnChange);
   clang_complete->NotifyView(path);
@@ -21,13 +21,13 @@ void MessageHandler::textDocument_didChange(TextDocumentDidChangeParam &param) {
 
 void MessageHandler::textDocument_didClose(TextDocumentParam &param) {
   std::string path = param.textDocument.uri.GetPath();
-  working_files->OnClose(param.textDocument);
+  wfiles->OnClose(param.textDocument);
   clang_complete->OnClose(path);
 }
 
 void MessageHandler::textDocument_didOpen(DidOpenTextDocumentParam &param) {
   std::string path = param.textDocument.uri.GetPath();
-  WorkingFile *working_file = working_files->OnOpen(param.textDocument);
+  WorkingFile *working_file = wfiles->OnOpen(param.textDocument);
   if (std::optional<std::string> cached_file_contents =
           pipeline::LoadIndexedContent(path))
     working_file->SetIndexContent(*cached_file_contents);
diff --git a/src/messages/textDocument_document.cc b/src/messages/textDocument_document.cc
index 9142683d..b72dc13a 100644
--- a/src/messages/textDocument_document.cc
+++ b/src/messages/textDocument_document.cc
@@ -3,7 +3,7 @@
 
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 #include <algorithm>
 
@@ -36,7 +36,7 @@ void MessageHandler::textDocument_documentHighlight(
   if (!file)
     return;
 
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   std::vector<DocumentHighlight> result;
 
   std::vector<SymbolRef> syms =
@@ -50,7 +50,7 @@ void MessageHandler::textDocument_documentHighlight(
           return usr == sym1.usr && kind == sym1.kind;
         }))
       continue;
-    if (auto loc = GetLsLocation(db, working_files, sym, file_id)) {
+    if (auto loc = GetLsLocation(db, wfiles, sym, file_id)) {
       DocumentHighlight highlight;
       highlight.range = loc->range;
       if (sym.role & Role::Write)
@@ -136,7 +136,7 @@ void MessageHandler::textDocument_documentSymbol(Reader &reader,
   QueryFile *file = FindFile(reply, param.textDocument.uri.GetPath(), &file_id);
   if (!file)
     return;
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   if (!wfile)
     return;
 
@@ -146,7 +146,7 @@ void MessageHandler::textDocument_documentSymbol(Reader &reader,
       if (refcnt > 0 && (param.all || sym.extent.Valid()) &&
           param.startLine <= sym.range.start.line &&
           sym.range.start.line <= param.endLine)
-        if (auto loc = GetLsLocation(db, working_files, sym, file_id))
+        if (auto loc = GetLsLocation(db, wfiles, sym, file_id))
           result.push_back(loc->range);
     std::sort(result.begin(), result.end());
     reply(result);
@@ -238,7 +238,7 @@ void MessageHandler::textDocument_documentSymbol(Reader &reader,
              Ignore(db->GetType(sym).AnyDef())) ||
             (sym.kind == SymbolKind::Var && Ignore(db->GetVar(sym).AnyDef())))
           continue;
-        if (auto loc = GetLsLocation(db, working_files, sym, file_id)) {
+        if (auto loc = GetLsLocation(db, wfiles, sym, file_id)) {
           info->location = *loc;
           result.push_back(*info);
         }
diff --git a/src/messages/textDocument_foldingRange.cc b/src/messages/textDocument_foldingRange.cc
index 53266cae..19258e25 100644
--- a/src/messages/textDocument_foldingRange.cc
+++ b/src/messages/textDocument_foldingRange.cc
@@ -4,8 +4,8 @@
 #include "message_handler.hh"
 #include "pipeline.hh"
 #include "project.hh"
-#include "query_utils.h"
-#include "working_files.h"
+#include "query_utils.hh"
+#include "working_files.hh"
 
 namespace ccls {
 namespace {
@@ -22,7 +22,7 @@ void MessageHandler::textDocument_foldingRange(TextDocumentParam &param,
   QueryFile *file = FindFile(reply, param.textDocument.uri.GetPath());
   if (!file)
     return;
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   if (!wfile)
     return;
   std::vector<FoldingRange> result;
diff --git a/src/messages/textDocument_formatting.cc b/src/messages/textDocument_formatting.cc
index 50987967..f81c675f 100644
--- a/src/messages/textDocument_formatting.cc
+++ b/src/messages/textDocument_formatting.cc
@@ -3,7 +3,7 @@
 
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "working_files.h"
+#include "working_files.hh"
 
 #include <clang/Format/Format.h>
 #include <clang/Tooling/Core/Replacement.h>
@@ -75,7 +75,7 @@ void MessageHandler::textDocument_formatting(DocumentFormattingParam &param,
   QueryFile *file = FindFile(reply, param.textDocument.uri.GetPath());
   if (!file)
     return;
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   if (!wfile)
     return;
   Format(reply, wfile, {0, (unsigned)wfile->buffer_content.size()});
@@ -86,7 +86,7 @@ void MessageHandler::textDocument_onTypeFormatting(
   QueryFile *file = FindFile(reply, param.textDocument.uri.GetPath());
   if (!file)
     return;
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   if (!wfile)
     return;
   std::string_view code = wfile->buffer_content;
@@ -102,7 +102,7 @@ void MessageHandler::textDocument_rangeFormatting(
   QueryFile *file = FindFile(reply, param.textDocument.uri.GetPath());
   if (!file)
     return;
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   if (!wfile)
     return;
   std::string_view code = wfile->buffer_content;
diff --git a/src/messages/textDocument_hover.cc b/src/messages/textDocument_hover.cc
index 6c2df0a7..a7f291e2 100644
--- a/src/messages/textDocument_hover.cc
+++ b/src/messages/textDocument_hover.cc
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "message_handler.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 namespace ccls {
 namespace {
@@ -85,12 +85,12 @@ void MessageHandler::textDocument_hover(TextDocumentPositionParam &param,
   if (!file)
     return;
 
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   Hover result;
 
   for (SymbolRef sym : FindSymbolsAtLocation(wfile, file, param.position)) {
     std::optional<lsRange> ls_range = GetLsRange(
-        working_files->GetFileByFilename(file->def->path), sym.range);
+        wfiles->GetFileByFilename(file->def->path), sym.range);
     if (!ls_range)
       continue;
 
diff --git a/src/messages/textDocument_references.cc b/src/messages/textDocument_references.cc
index 2a9f4e26..d8be0be4 100644
--- a/src/messages/textDocument_references.cc
+++ b/src/messages/textDocument_references.cc
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "message_handler.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 #include <unordered_set>
 
@@ -31,7 +31,7 @@ void MessageHandler::textDocument_references(Reader &reader, ReplyOnce &reply) {
   if (!file)
     return;
   std::vector<lsLocation> result;
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   if (!file)
     return;
 
@@ -52,7 +52,7 @@ void MessageHandler::textDocument_references(Reader &reader, ReplyOnce &reply) {
         if (Role(use.role & param.context.role) == param.context.role &&
             !(use.role & param.context.excludeRole) &&
             seen_uses.insert(use).second)
-          if (auto loc = GetLsLocation(db, working_files, use)) {
+          if (auto loc = GetLsLocation(db, wfiles, use)) {
             result.push_back(*loc);
           }
       };
diff --git a/src/messages/textDocument_rename.cc b/src/messages/textDocument_rename.cc
index 1d21c96e..4dd8f5e2 100644
--- a/src/messages/textDocument_rename.cc
+++ b/src/messages/textDocument_rename.cc
@@ -2,17 +2,17 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "message_handler.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 namespace ccls {
 namespace {
-lsWorkspaceEdit BuildWorkspaceEdit(DB *db, WorkingFiles *working_files,
+lsWorkspaceEdit BuildWorkspaceEdit(DB *db, WorkingFiles *wfiles,
                                    SymbolRef sym, const std::string &new_text) {
   std::unordered_map<int, lsTextDocumentEdit> path_to_edit;
 
   EachOccurrence(db, sym, true, [&](Use use) {
     std::optional<lsLocation> ls_location =
-        GetLsLocation(db, working_files, use);
+        GetLsLocation(db, wfiles, use);
     if (!ls_location)
       return;
 
@@ -27,7 +27,7 @@ lsWorkspaceEdit BuildWorkspaceEdit(DB *db, WorkingFiles *working_files,
       const std::string &path = file.def->path;
       path_to_edit[file_id].textDocument.uri = lsDocumentUri::FromPath(path);
 
-      WorkingFile *working_file = working_files->GetFileByFilename(path);
+      WorkingFile *working_file = wfiles->GetFileByFilename(path);
       if (working_file)
         path_to_edit[file_id].textDocument.version = working_file->version;
     }
@@ -55,10 +55,10 @@ void MessageHandler::textDocument_rename(RenameParam &param, ReplyOnce &reply) {
   if (!file)
     return;
 
-  WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+  WorkingFile *wfile = wfiles->GetFileByFilename(file->def->path);
   lsWorkspaceEdit result;
   for (SymbolRef sym : FindSymbolsAtLocation(wfile, file, param.position)) {
-    result = BuildWorkspaceEdit(db, working_files, sym, param.newName);
+    result = BuildWorkspaceEdit(db, wfiles, sym, param.newName);
     break;
   }
 
diff --git a/src/messages/textDocument_signatureHelp.cc b/src/messages/textDocument_signatureHelp.cc
index c58e42f8..dd995340 100644
--- a/src/messages/textDocument_signatureHelp.cc
+++ b/src/messages/textDocument_signatureHelp.cc
@@ -144,7 +144,7 @@ void MessageHandler::textDocument_signatureHelp(
 
   std::string path = param.textDocument.uri.GetPath();
   lsPosition begin_pos = param.position;
-  if (WorkingFile *file = working_files->GetFileByFilename(path)) {
+  if (WorkingFile *file = wfiles->GetFileByFilename(path)) {
     std::string completion_text;
     lsPosition end_pos = param.position;
     begin_pos = file->FindStableCompletionSource(param.position,
diff --git a/src/messages/workspace.cc b/src/messages/workspace.cc
index 289896a0..c07effe3 100644
--- a/src/messages/workspace.cc
+++ b/src/messages/workspace.cc
@@ -2,12 +2,12 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "clang_complete.hh"
-#include "fuzzy_match.h"
+#include "fuzzy_match.hh"
 #include "log.hh"
 #include "message_handler.hh"
 #include "pipeline.hh"
 #include "project.hh"
-#include "query_utils.h"
+#include "query_utils.hh"
 
 #include <llvm/ADT/STLExtras.h>
 
@@ -22,7 +22,7 @@ MAKE_REFLECT_STRUCT(lsSymbolInformation, name, kind, location, containerName);
 void MessageHandler::workspace_didChangeConfiguration(EmptyParam &) {
   for (const std::string &folder : g_config->workspaceFolders)
     project->Load(folder);
-  project->Index(working_files, lsRequestId());
+  project->Index(wfiles, lsRequestId());
 
   clang_complete->FlushAllSessions();
 };
@@ -31,7 +31,7 @@ void MessageHandler::workspace_didChangeWatchedFiles(
     DidChangeWatchedFilesParam &param) {
   for (auto &event : param.changes) {
     std::string path = event.uri.GetPath();
-    IndexMode mode = working_files->GetFileByFilename(path)
+    IndexMode mode = wfiles->GetFileByFilename(path)
                          ? IndexMode::Normal
                          : IndexMode::NonInteractive;
     switch (event.type) {
@@ -76,7 +76,7 @@ void MessageHandler::workspace_didChangeWorkspaceFolders(
     project->Load(root);
   }
 
-  project->Index(working_files, lsRequestId());
+  project->Index(wfiles, lsRequestId());
 
   clang_complete->FlushAllSessions();
 }
@@ -84,7 +84,7 @@ void MessageHandler::workspace_didChangeWorkspaceFolders(
 namespace {
 // Lookup |symbol| in |db| and insert the value into |result|.
 bool AddSymbol(
-    DB *db, WorkingFiles *working_files, SymbolIdx sym, bool use_detailed,
+    DB *db, WorkingFiles *wfiles, SymbolIdx sym, bool use_detailed,
     std::vector<std::tuple<lsSymbolInformation, int, SymbolIdx>> *result) {
   std::optional<lsSymbolInformation> info = GetSymbolInfo(db, sym, true);
   if (!info)
@@ -100,7 +100,7 @@ bool AddSymbol(
     loc = decls[0];
   }
 
-  std::optional<lsLocation> ls_location = GetLsLocation(db, working_files, loc);
+  std::optional<lsLocation> ls_location = GetLsLocation(db, wfiles, loc);
   if (!ls_location)
     return false;
   info->location = *ls_location;
@@ -129,7 +129,7 @@ void MessageHandler::workspace_symbol(WorkspaceSymbolParam &param,
     std::string_view detailed_name = db->GetSymbolName(sym, true);
     int pos = ReverseSubseqMatch(query_without_space, detailed_name, sensitive);
     return pos >= 0 &&
-           AddSymbol(db, working_files, sym,
+           AddSymbol(db, wfiles, sym,
                      detailed_name.find(':', pos) != std::string::npos,
                      &cands) &&
            cands.size() >= g_config->workspaceSymbol.maxNum;
diff --git a/src/pipeline.cc b/src/pipeline.cc
index 3a920374..5bb20457 100644
--- a/src/pipeline.cc
+++ b/src/pipeline.cc
@@ -4,17 +4,17 @@
 #include "pipeline.hh"
 
 #include "clang_complete.hh"
-#include "config.h"
-#include "include_complete.h"
+#include "config.hh"
+#include "include_complete.hh"
 #include "log.hh"
 #include "lsp.hh"
-#include "match.h"
+#include "match.hh"
 #include "message_handler.hh"
 #include "pipeline.hh"
-#include "platform.h"
+#include "platform.hh"
 #include "project.hh"
-#include "query_utils.h"
-#include "serializers/json.h"
+#include "query_utils.hh"
+#include "serializers/json.hh"
 
 #include <rapidjson/document.h>
 #include <rapidjson/writer.h>
@@ -365,12 +365,12 @@ void Indexer_Main(CompletionManager *completion, VFS *vfs, Project *project,
       indexer_waiter->Wait(index_request);
 }
 
-void Main_OnIndexed(DB *db, WorkingFiles *working_files, IndexUpdate *update) {
+void Main_OnIndexed(DB *db, WorkingFiles *wfiles, IndexUpdate *update) {
   if (update->refresh) {
     LOG_S(INFO)
         << "loaded project. Refresh semantic highlight for all working file.";
-    std::lock_guard<std::mutex> lock(working_files->files_mutex);
-    for (auto &f : working_files->files) {
+    std::lock_guard<std::mutex> lock(wfiles->files_mutex);
+    for (auto &f : wfiles->files) {
       std::string filename = LowerPathIfInsensitive(f->filename);
       if (db->name2file_id.find(filename) == db->name2file_id.end())
         continue;
@@ -389,7 +389,7 @@ void Main_OnIndexed(DB *db, WorkingFiles *working_files, IndexUpdate *update) {
   if (update->files_def_update) {
     auto &def_u = *update->files_def_update;
     if (WorkingFile *wfile =
-            working_files->GetFileByFilename(def_u.first.path)) {
+            wfiles->GetFileByFilename(def_u.first.path)) {
       // FIXME With index.onChange: true, use buffer_content only for
       // request.path
       wfile->SetIndexContent(g_config->index.onChange ? wfile->buffer_content
@@ -475,11 +475,11 @@ void LaunchStdout() {
 
 void MainLoop() {
   Project project;
-  WorkingFiles working_files;
+  WorkingFiles wfiles;
   VFS vfs;
 
   CompletionManager clang_complete(
-      &project, &working_files,
+      &project, &wfiles,
       [&](std::string path, std::vector<lsDiagnostic> diagnostics) {
         lsPublishDiagnosticsParams params;
         params.uri = lsDocumentUri::FromPath(path);
@@ -503,7 +503,7 @@ void MainLoop() {
   handler.db = &db;
   handler.project = &project;
   handler.vfs = &vfs;
-  handler.working_files = &working_files;
+  handler.wfiles = &wfiles;
   handler.clang_complete = &clang_complete;
   handler.include_complete = &include_complete;
 
@@ -521,7 +521,7 @@ void MainLoop() {
         break;
       did_work = true;
       indexed = true;
-      Main_OnIndexed(&db, &working_files, &*update);
+      Main_OnIndexed(&db, &wfiles, &*update);
     }
 
     if (did_work)
@@ -544,7 +544,7 @@ void Standalone(const std::string &root) {
 
   MessageHandler handler;
   handler.project = &project;
-  handler.working_files = &wfiles;
+  handler.wfiles = &wfiles;
   handler.vfs = &vfs;
   handler.include_complete = &complete;
 
diff --git a/src/pipeline.hh b/src/pipeline.hh
index 3e3b1861..6ac8bdf0 100644
--- a/src/pipeline.hh
+++ b/src/pipeline.hh
@@ -4,7 +4,7 @@
 #pragma once
 
 #include "lsp.hh"
-#include "query.h"
+#include "query.hh"
 
 #include <atomic>
 #include <mutex>
diff --git a/src/platform.h b/src/platform.hh
similarity index 100%
rename from src/platform.h
rename to src/platform.hh
diff --git a/src/platform_posix.cc b/src/platform_posix.cc
index 1f848fbe..52e19fc8 100644
--- a/src/platform_posix.cc
+++ b/src/platform_posix.cc
@@ -2,9 +2,9 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #if defined(__unix__) || defined(__APPLE__)
-#include "platform.h"
+#include "platform.hh"
 
-#include "utils.h"
+#include "utils.hh"
 
 #include <assert.h>
 #include <limits.h>
diff --git a/src/platform_win.cc b/src/platform_win.cc
index a051cd7b..c892c2bd 100644
--- a/src/platform_win.cc
+++ b/src/platform_win.cc
@@ -2,9 +2,9 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #if defined(_WIN32)
-#include "platform.h"
+#include "platform.hh"
 
-#include "utils.h"
+#include "utils.hh"
 
 #include <Windows.h>
 #include <direct.h>
diff --git a/src/position.cc b/src/position.cc
index 12748374..39f03f3f 100644
--- a/src/position.cc
+++ b/src/position.cc
@@ -1,7 +1,7 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "position.h"
+#include "position.hh"
 
 #include "serializer.hh"
 
diff --git a/src/position.h b/src/position.hh
similarity index 97%
rename from src/position.h
rename to src/position.hh
index a90d4c7a..67843d78 100644
--- a/src/position.h
+++ b/src/position.hh
@@ -3,8 +3,8 @@
 
 #pragma once
 
-#include "maybe.h"
-#include "utils.h"
+#include "maybe.hh"
+#include "utils.hh"
 
 #include <stdint.h>
 #include <string>
diff --git a/src/project.cc b/src/project.cc
index 90315b88..f547d6a2 100644
--- a/src/project.cc
+++ b/src/project.cc
@@ -5,12 +5,12 @@
 
 #include "filesystem.hh"
 #include "log.hh"
-#include "match.h"
+#include "match.hh"
 #include "pipeline.hh"
-#include "platform.h"
-#include "serializers/json.h"
-#include "utils.h"
-#include "working_files.h"
+#include "platform.hh"
+#include "serializers/json.hh"
+#include "utils.hh"
+#include "working_files.hh"
 
 #include <clang/Driver/Compilation.h>
 #include <clang/Driver/Driver.h>
diff --git a/src/project.hh b/src/project.hh
index 92d50df4..b176f24f 100644
--- a/src/project.hh
+++ b/src/project.hh
@@ -3,7 +3,7 @@
 
 #pragma once
 
-#include "config.h"
+#include "config.hh"
 #include "lsp.hh"
 
 #include <functional>
diff --git a/src/query.cc b/src/query.cc
index 8bc294c6..b29b8d1c 100644
--- a/src/query.cc
+++ b/src/query.cc
@@ -1,11 +1,11 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "query.h"
+#include "query.hh"
 
-#include "indexer.h"
+#include "indexer.hh"
 #include "serializer.hh"
-#include "serializers/json.h"
+#include "serializers/json.hh"
 
 #include <cassert>
 #include <cstdint>
diff --git a/src/query.h b/src/query.hh
similarity index 99%
rename from src/query.h
rename to src/query.hh
index bccb6b1d..ad255373 100644
--- a/src/query.h
+++ b/src/query.hh
@@ -3,7 +3,7 @@
 
 #pragma once
 
-#include "indexer.h"
+#include "indexer.hh"
 #include "serializer.hh"
 
 #include <llvm/ADT/DenseMap.h>
diff --git a/src/query_utils.cc b/src/query_utils.cc
index d950f1d6..d1c5ff2f 100644
--- a/src/query_utils.cc
+++ b/src/query_utils.cc
@@ -1,7 +1,7 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "query_utils.h"
+#include "query_utils.hh"
 
 #include "pipeline.hh"
 
diff --git a/src/query_utils.h b/src/query_utils.hh
similarity index 98%
rename from src/query_utils.h
rename to src/query_utils.hh
index eb95022d..3eb1e81a 100644
--- a/src/query_utils.h
+++ b/src/query_utils.hh
@@ -3,8 +3,8 @@
 
 #pragma once
 
-#include "query.h"
-#include "working_files.h"
+#include "query.hh"
+#include "working_files.hh"
 
 #include <optional>
 
diff --git a/src/serializer.cc b/src/serializer.cc
index 7243ea42..4bf20c5e 100644
--- a/src/serializer.cc
+++ b/src/serializer.cc
@@ -4,10 +4,10 @@
 #include "serializer.hh"
 
 #include "filesystem.hh"
-#include "indexer.h"
+#include "indexer.hh"
 #include "log.hh"
-#include "serializers/binary.h"
-#include "serializers/json.h"
+#include "serializers/binary.hh"
+#include "serializers/json.hh"
 
 #include <llvm/ADT/CachedHashString.h>
 #include <llvm/ADT/DenseSet.h>
diff --git a/src/serializer.hh b/src/serializer.hh
index 98614f1d..189ca855 100644
--- a/src/serializer.hh
+++ b/src/serializer.hh
@@ -3,7 +3,7 @@
 
 #pragma once
 
-#include "maybe.h"
+#include "maybe.hh"
 
 #include <llvm/Support/Compiler.h>
 
diff --git a/src/serializers/binary.h b/src/serializers/binary.hh
similarity index 100%
rename from src/serializers/binary.h
rename to src/serializers/binary.hh
diff --git a/src/serializers/json.h b/src/serializers/json.hh
similarity index 100%
rename from src/serializers/json.h
rename to src/serializers/json.hh
diff --git a/src/test.cc b/src/test.cc
index bb488e23..b7c8a2b7 100644
--- a/src/test.cc
+++ b/src/test.cc
@@ -1,15 +1,15 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "test.h"
+#include "test.hh"
 
 #include "clang_complete.hh"
 #include "filesystem.hh"
-#include "indexer.h"
+#include "indexer.hh"
 #include "pipeline.hh"
-#include "platform.h"
+#include "platform.hh"
 #include "serializer.hh"
-#include "utils.h"
+#include "utils.hh"
 
 #include <llvm/Config/llvm-config.h>
 #include <llvm/ADT/StringRef.h>
diff --git a/src/test.h b/src/test.hh
similarity index 100%
rename from src/test.h
rename to src/test.hh
diff --git a/src/threaded_queue.h b/src/threaded_queue.hh
similarity index 99%
rename from src/threaded_queue.h
rename to src/threaded_queue.hh
index ab514d12..5d07640c 100644
--- a/src/threaded_queue.h
+++ b/src/threaded_queue.hh
@@ -3,7 +3,7 @@
 
 #pragma once
 
-#include "utils.h"
+#include "utils.hh"
 
 #include <atomic>
 #include <condition_variable>
diff --git a/src/utils.cc b/src/utils.cc
index 8cd824d0..950aef04 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -1,10 +1,10 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "utils.h"
+#include "utils.hh"
 
 #include "log.hh"
-#include "platform.h"
+#include "platform.hh"
 
 #include <siphash.h>
 
diff --git a/src/utils.h b/src/utils.hh
similarity index 100%
rename from src/utils.h
rename to src/utils.hh
diff --git a/src/working_files.cc b/src/working_files.cc
index 93316ded..fe8ecc83 100644
--- a/src/working_files.cc
+++ b/src/working_files.cc
@@ -1,10 +1,10 @@
 // Copyright 2017-2018 ccls Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include "working_files.h"
+#include "working_files.hh"
 
 #include "log.hh"
-#include "position.h"
+#include "position.hh"
 
 #include <algorithm>
 #include <climits>
diff --git a/src/working_files.h b/src/working_files.hh
similarity index 99%
rename from src/working_files.h
rename to src/working_files.hh
index 09ccf31a..a268c127 100644
--- a/src/working_files.h
+++ b/src/working_files.hh
@@ -4,7 +4,7 @@
 #pragma once
 
 #include "lsp.hh"
-#include "utils.h"
+#include "utils.hh"
 
 #include <mutex>
 #include <optional>