diff --git a/src/config.hh b/src/config.hh
index ca914dc6..bc8da9ae 100644
--- a/src/config.hh
+++ b/src/config.hh
@@ -102,6 +102,8 @@ struct Config {
   } clang;
 
   struct ClientCapability {
+    // TextDocumentClientCapabilities.publishDiagnostics.relatedInformation
+    bool diagnosticsRelatedInformation = true;
     // TextDocumentClientCapabilities.documentSymbol.hierarchicalDocumentSymbolSupport
     bool hierarchicalDocumentSymbolSupport = true;
     // TextDocumentClientCapabilities.definition.linkSupport
@@ -299,8 +301,8 @@ REFLECT_STRUCT(Config::ServerCap, documentOnTypeFormattingProvider,
                foldingRangeProvider, workspace);
 REFLECT_STRUCT(Config::Clang, excludeArgs, extraArgs, pathMappings,
                resourceDir);
-REFLECT_STRUCT(Config::ClientCapability, hierarchicalDocumentSymbolSupport,
-               linkSupport, snippetSupport);
+REFLECT_STRUCT(Config::ClientCapability, diagnosticsRelatedInformation,
+               hierarchicalDocumentSymbolSupport, linkSupport, snippetSupport);
 REFLECT_STRUCT(Config::CodeLens, localVariables);
 REFLECT_STRUCT(Config::Completion::Include, blacklist, maxPathSize,
                suffixWhitelist, whitelist);
diff --git a/src/lsp.hh b/src/lsp.hh
index 8f8efda9..b92578b8 100644
--- a/src/lsp.hh
+++ b/src/lsp.hh
@@ -238,12 +238,18 @@ struct WorkspaceFolder {
 enum class MessageType : int { Error = 1, Warning = 2, Info = 3, Log = 4 };
 REFLECT_UNDERLYING(MessageType)
 
+struct DiagnosticRelatedInformation {
+  Location location;
+  std::string message;
+};
+
 struct Diagnostic {
   lsRange range;
   int severity = 0;
   int code = 0;
   std::string source = "ccls";
   std::string message;
+  std::vector<DiagnosticRelatedInformation> relatedInformation;
   std::vector<TextEdit> fixits_;
 };
 
diff --git a/src/message_handler.hh b/src/message_handler.hh
index 949fc242..61d7e1c3 100644
--- a/src/message_handler.hh
+++ b/src/message_handler.hh
@@ -195,7 +195,8 @@ REFLECT_STRUCT(TextDocumentIdentifier, uri);
 REFLECT_STRUCT(TextDocumentItem, uri, languageId, version, text);
 REFLECT_STRUCT(TextEdit, range, newText);
 REFLECT_STRUCT(VersionedTextDocumentIdentifier, uri, version);
-REFLECT_STRUCT(Diagnostic, range, severity, code, source, message);
+REFLECT_STRUCT(DiagnosticRelatedInformation, location, message);
+REFLECT_STRUCT(Diagnostic, range, severity, code, source, message, relatedInformation);
 REFLECT_STRUCT(ShowMessageParam, type, message);
 REFLECT_UNDERLYING_B(LanguageId);
 
diff --git a/src/messages/initialize.cc b/src/messages/initialize.cc
index 6259e8d0..707798d0 100644
--- a/src/messages/initialize.cc
+++ b/src/messages/initialize.cc
@@ -171,6 +171,10 @@ struct TextDocumentClientCap {
   struct DocumentSymbol {
     bool hierarchicalDocumentSymbolSupport = false;
   } documentSymbol;
+
+  struct PublishDiagnostics {
+    bool relatedInformation = false;
+  } publishDiagnostics;
 };
 
 REFLECT_STRUCT(TextDocumentClientCap::Completion::CompletionItem,
@@ -179,7 +183,8 @@ REFLECT_STRUCT(TextDocumentClientCap::Completion, completionItem);
 REFLECT_STRUCT(TextDocumentClientCap::DocumentSymbol,
                hierarchicalDocumentSymbolSupport);
 REFLECT_STRUCT(TextDocumentClientCap::LinkSupport, linkSupport);
-REFLECT_STRUCT(TextDocumentClientCap, completion, definition, documentSymbol);
+REFLECT_STRUCT(TextDocumentClientCap::PublishDiagnostics, relatedInformation);
+REFLECT_STRUCT(TextDocumentClientCap, completion, definition, documentSymbol, publishDiagnostics);
 
 struct ClientCap {
   WorkspaceClientCap workspace;
@@ -306,6 +311,8 @@ void Initialize(MessageHandler *m, InitializeParam &param, ReplyOnce &reply) {
       capabilities.textDocument.definition.linkSupport;
   g_config->client.snippetSupport &=
       capabilities.textDocument.completion.completionItem.snippetSupport;
+  g_config->client.diagnosticsRelatedInformation &=
+      capabilities.textDocument.publishDiagnostics.relatedInformation;
   didChangeWatchedFiles =
       capabilities.workspace.didChangeWatchedFiles.dynamicRegistration;
 
diff --git a/src/sema_manager.cc b/src/sema_manager.cc
index a80bd0d7..d78b5e06 100644
--- a/src/sema_manager.cc
+++ b/src/sema_manager.cc
@@ -514,7 +514,7 @@ llvm::StringRef diagLeveltoString(DiagnosticsEngine::Level Lvl) {
   }
 }
 
-void printDiag(llvm::raw_string_ostream &OS, const DiagBase &d) {
+void PrintDiag(llvm::raw_string_ostream &OS, const DiagBase &d) {
   if (d.concerned)
     OS << llvm::sys::path::filename(d.file);
   else
@@ -612,27 +612,40 @@ void *DiagnosticMain(void *manager_) {
     for (auto &d : diags) {
       if (!d.concerned)
         continue;
-      std::string buf;
-      llvm::raw_string_ostream OS(buf);
       Diagnostic &ls_diag = ls_diags.emplace_back();
       Fill(d, ls_diag);
       ls_diag.fixits_ = d.edits;
-      OS << d.message;
-      for (auto &n : d.notes) {
-        OS << "\n\n";
-        printDiag(OS, n);
-      }
-      OS.flush();
-      ls_diag.message = std::move(buf);
-      for (auto &n : d.notes) {
-        if (!n.concerned)
-          continue;
-        Diagnostic &ls_diag1 = ls_diags.emplace_back();
-        Fill(n, ls_diag1);
-        OS << n.message << "\n\n";
-        printDiag(OS, d);
+      if (g_config->client.diagnosticsRelatedInformation) {
+        ls_diag.message = d.message;
+        for (const Note &n : d.notes) {
+          SmallString<256> Str(n.file);
+          llvm::sys::path::remove_dots(Str, true);
+          Location loc{DocumentUri::FromPath(Str.str()),
+                       lsRange{{n.range.start.line, n.range.start.column},
+                               {n.range.end.line, n.range.end.column}}};
+          ls_diag.relatedInformation.push_back({loc, n.message});
+        }
+      } else {
+        std::string buf;
+        llvm::raw_string_ostream OS(buf);
+        OS << d.message;
+        for (const Note &n : d.notes) {
+          OS << "\n\n";
+          PrintDiag(OS, n);
+        }
         OS.flush();
-        ls_diag1.message = std::move(buf);
+        ls_diag.message = std::move(buf);
+        for (const Note &n : d.notes) {
+          if (!n.concerned)
+            continue;
+          Diagnostic &ls_diag1 = ls_diags.emplace_back();
+          Fill(n, ls_diag1);
+          buf.clear();
+          OS << n.message << "\n\n";
+          PrintDiag(OS, d);
+          OS.flush();
+          ls_diag1.message = std::move(buf);
+        }
       }
     }