diff --git a/src/clang_complete.cc b/src/clang_complete.cc
index 734dcf30..8584b5ad 100644
--- a/src/clang_complete.cc
+++ b/src/clang_complete.cc
@@ -802,3 +802,17 @@ std::shared_ptr<CompletionSession> ClangCompleteManager::TryGetSession(
 
   return completion_session;
 }
+
+void ClangCompleteManager::FlushSession(const std::string& filename) {
+	std::lock_guard<std::mutex> lock(sessions_lock_);
+
+	preloaded_sessions_.TryTake(filename);
+	completion_sessions_.TryTake(filename);
+}
+
+void ClangCompleteManager::FlushAllSessions() {
+	std::lock_guard<std::mutex> lock(sessions_lock_);
+
+	preloaded_sessions_.Clear();
+	completion_sessions_.Clear();
+}
diff --git a/src/clang_complete.h b/src/clang_complete.h
index ef506005..03197a60 100644
--- a/src/clang_complete.h
+++ b/src/clang_complete.h
@@ -110,6 +110,11 @@ struct ClangCompleteManager {
                                                    bool mark_as_completion,
                                                    bool create_if_needed);
 
+  // Flushes all saved sessions with the supplied filename
+  void FlushSession(const std::string& filename);
+  // Flushes all saved sessions
+  void FlushAllSessions(void);
+
   // TODO: make these configurable.
   const int kMaxPreloadedSessions = 10;
   const int kMaxCompletionSessions = 5;
diff --git a/src/diagnostics_engine.cc b/src/diagnostics_engine.cc
index 36453ea2..15253d1d 100644
--- a/src/diagnostics_engine.cc
+++ b/src/diagnostics_engine.cc
@@ -13,11 +13,6 @@ void DiagnosticsEngine::Init(Config* config) {
 void DiagnosticsEngine::Publish(WorkingFiles* working_files,
                                 std::string path,
                                 std::vector<lsDiagnostic> diagnostics) {
-  // Cache diagnostics so we can show fixits.
-  working_files->DoActionOnFile(path, [&](WorkingFile* working_file) {
-    if (working_file)
-      working_file->diagnostics_ = diagnostics;
-  });
 
   int64_t now =
       std::chrono::duration_cast<std::chrono::milliseconds>(
diff --git a/src/import_pipeline.cc b/src/import_pipeline.cc
index 3fcff636..03d8f47c 100644
--- a/src/import_pipeline.cc
+++ b/src/import_pipeline.cc
@@ -408,6 +408,12 @@ void ParseFile(Config* config,
   for (std::unique_ptr<IndexFile>& new_index : *indexes) {
     Timer time;
 
+    // Cache diagnostics so we can show fixits.
+    working_files->DoActionOnFile(path, [&](WorkingFile* working_file) {
+      if (working_file)
+        working_file->diagnostics_ = diagnostics;
+    });
+
     // Only emit diagnostics for non-interactive sessions, which makes it easier
     // to identify indexing problems. For interactive sessions, diagnostics are
     // handled by code completion.
diff --git a/src/lru_cache.h b/src/lru_cache.h
index 5539cc78..c6e3d9c4 100644
--- a/src/lru_cache.h
+++ b/src/lru_cache.h
@@ -29,6 +29,9 @@ struct LruCache {
   template <typename TFunc>
   void IterateValues(TFunc func);
 
+  // Empties the cache
+  void Clear(void);
+
  private:
   // There is a global score counter, when we access an element we increase
   // its score to the current global value, so it has the highest overall
@@ -124,3 +127,9 @@ void LruCache<TKey, TValue>::IncrementScore() {
       entry.score = next_score_++;
   }
 }
+
+template <typename TKey, typename TValue>
+void LruCache<TKey, TValue>::Clear(void) {
+	entries_.clear();
+	next_score_ = 0;
+}
diff --git a/src/messages/workspace_did_change_configuration.cc b/src/messages/workspace_did_change_configuration.cc
index 7b90fc8d..3506cf59 100644
--- a/src/messages/workspace_did_change_configuration.cc
+++ b/src/messages/workspace_did_change_configuration.cc
@@ -1,10 +1,13 @@
 #include "cache_manager.h"
+#include "clang_complete.h"
 #include "message_handler.h"
 #include "project.h"
 #include "queue_manager.h"
 #include "timer.h"
 #include "working_files.h"
 
+#include <loguru.hpp>
+
 namespace {
 struct lsDidChangeConfigurationParams {
   bool placeholder;
@@ -32,6 +35,9 @@ struct WorkspaceDidChangeConfigurationHandler
                    std::monostate());
     time.ResetAndPrint(
         "[perf] Dispatched workspace/didChangeConfiguration index requests");
+
+    clang_complete->FlushAllSessions();
+    LOG_S(INFO) << "Flushed all clang complete sessions";
   }
 };
 REGISTER_MESSAGE_HANDLER(WorkspaceDidChangeConfigurationHandler);