diff --git a/src/file_consumer.cc b/src/file_consumer.cc
index eb3a9a7c..680e6ebc 100644
--- a/src/file_consumer.cc
+++ b/src/file_consumer.cc
@@ -1,36 +1,66 @@
 #include "file_consumer.h"
 
 #include "indexer.h"
+#include "platform.h"
 #include "utils.h"
 
+namespace {
+
+std::string FileName(CXFile file) {
+  CXString cx_name = clang_getFileName(file);
+  std::string name = clang::ToString(cx_name);
+  return NormalizePath(name);
+}
+
+}  // namespace
+
+bool operator==(const CXFileUniqueID& a, const CXFileUniqueID& b) {
+  return a.data[0] == b.data[0] && a.data[1] == b.data[1] && a.data[2] == b.data[2];
+}
+
 FileConsumer::FileConsumer(SharedState* shared_state) : shared_(shared_state) {}
 
-IndexedFile* FileConsumer::TryConsumeFile(const std::string& file, bool* is_first_ownership) {
+IndexedFile* FileConsumer::TryConsumeFile(CXFile file, bool* is_first_ownership) {
   assert(is_first_ownership);
 
+  CXFileUniqueID file_id;
+  if (clang_getFileUniqueID(file, &file_id) != 0) {
+    std::cerr << "Could not get unique file id for " << FileName(file) << std::endl;
+    return nullptr;
+  }
+
   // Try to find cached local result.
-  auto it = local_.find(file);
+  auto it = local_.find(file_id);
   if (it != local_.end()) {
     *is_first_ownership = false;
     return it->second.get();
   }
 
+  std::string file_name = FileName(file);
+
   // No result in local; we need to query global.
   bool did_insert = false;
   {
     std::lock_guard<std::mutex> lock(shared_->mutex);
-    did_insert = shared_->files.insert(file).second;
+    did_insert = shared_->files.insert(file_name).second;
   }
   *is_first_ownership = did_insert;
-  local_[file] = did_insert ? MakeUnique<IndexedFile>(file) : nullptr;
-  return local_[file].get();
+  local_[file_id] = did_insert ? MakeUnique<IndexedFile>(file_name) : nullptr;
+  return local_[file_id].get();
 }
 
-IndexedFile* FileConsumer::ForceLocal(const std::string& file) {
-  auto it = local_.find(file);
+IndexedFile* FileConsumer::ForceLocal(CXFile file) {
+  CXFileUniqueID file_id;
+  if (clang_getFileUniqueID(file, &file_id) != 0) {
+    std::cerr << "Could not get unique file id for " << FileName(file) << std::endl;
+    return nullptr;
+  }
+
+  auto it = local_.find(file_id);
   if (it == local_.end())
-    local_[file] = MakeUnique<IndexedFile>(file);
-  return local_[file].get();
+    local_[file_id] = MakeUnique<IndexedFile>(FileName(file));
+  assert(local_.find(file_id) != local_.end());
+  return local_[file_id].get();
 }
 
 std::vector<std::unique_ptr<IndexedFile>> FileConsumer::TakeLocalState() {
diff --git a/src/file_consumer.h b/src/file_consumer.h
index e628b301..671a72f9 100644
--- a/src/file_consumer.h
+++ b/src/file_consumer.h
@@ -1,11 +1,20 @@
 #pragma once
 
+#include "utils.h"
+
+#include <clang-c/Index.h>
+
+#include <functional>
 #include <mutex>
 #include <unordered_set>
 #include <unordered_map>
 
 struct IndexedFile;
 
+// Needed for unordered_map usage below.
+MAKE_HASHABLE(CXFileUniqueID, t.data[0], t.data[1], t.data[2]);
+bool operator==(const CXFileUniqueID& a, const CXFileUniqueID& b);
+
 // FileConsumer is used by the indexer. When it encouters a file, it tries to
 // take ownership over it. If the indexer has ownership over a file, it will
 // produce an index, otherwise, it will emit nothing for that declarations
@@ -27,15 +36,15 @@ struct FileConsumer {
   // Returns IndexedFile for the file or nullptr. |is_first_ownership| is set
   // to true iff the function just took ownership over the file. Otherwise it
   // is set to false.
-  IndexedFile* TryConsumeFile(const std::string& file, bool* is_first_ownership);
+  IndexedFile* TryConsumeFile(CXFile file, bool* is_first_ownership);
 
   // Forcibly create a local file, even if it has already been parsed.
-  IndexedFile* ForceLocal(const std::string& file);
+  IndexedFile* ForceLocal(CXFile file);
 
   // Returns and passes ownership of all local state.
   std::vector<std::unique_ptr<IndexedFile>> TakeLocalState();
 
  private:
-  std::unordered_map<std::string, std::unique_ptr<IndexedFile>> local_;
+  std::unordered_map<CXFileUniqueID, std::unique_ptr<IndexedFile>> local_;
   SharedState* shared_;
 };
\ No newline at end of file
diff --git a/src/indexer.cc b/src/indexer.cc
index 2e9f1c49..69e82cab 100644
--- a/src/indexer.cc
+++ b/src/indexer.cc
@@ -711,10 +711,9 @@ void indexDeclaration(CXClientData client_data, const CXIdxDeclInfo* decl) {
   // TODO: Use clang_getFileUniqueID
   CXFile file;
   clang_getSpellingLocation(clang_indexLoc_getCXSourceLocation(decl->loc), &file, nullptr, nullptr, nullptr);
-  std::string filename = NormalizePath(clang::ToString(clang_getFileName(file)));
   IndexParam* param = static_cast<IndexParam*>(client_data);
   bool is_first_time_visiting_file = false;
-  IndexedFile* db = param->file_consumer->TryConsumeFile(filename, &is_first_time_visiting_file);
+  IndexedFile* db = param->file_consumer->TryConsumeFile(file, &is_first_time_visiting_file);
   if (!db)
     return;
 
@@ -1170,10 +1169,9 @@ void indexEntityReference(CXClientData client_data,
   // TODO: Use clang_getFileUniqueID
   CXFile file;
   clang_getSpellingLocation(clang_indexLoc_getCXSourceLocation(ref->loc), &file, nullptr, nullptr, nullptr);
-  std::string filename = NormalizePath(clang::ToString(clang_getFileName(file)));
   IndexParam* param = static_cast<IndexParam*>(client_data);
   bool is_first_time_visiting_file = false;
-  IndexedFile* db = param->file_consumer->TryConsumeFile(filename, &is_first_time_visiting_file);
+  IndexedFile* db = param->file_consumer->TryConsumeFile(file, &is_first_time_visiting_file);
   if (!db)
     return;
 
@@ -1415,7 +1413,8 @@ std::vector<std::unique_ptr<IndexedFile>> Parse(FileConsumer* file_consumer, std
 
   IndexParam param(file_consumer);
 
-  param.primary_file = file_consumer->ForceLocal(filename);
+  CXFile file = clang_getFile(tu.cx_tu, filename.c_str());
+  param.primary_file = file_consumer->ForceLocal(file);
 
   std::cerr << "!! [START] Indexing " << filename << std::endl;
   CXIndexAction index_action = clang_IndexAction_create(index.cx_index);