diff --git a/server/MetasequoiaImeEngine b/server/MetasequoiaImeEngine
index 2e5302ad..40aa3fdc 160000
--- a/server/MetasequoiaImeEngine
+++ b/server/MetasequoiaImeEngine
@@ -1 +1 @@
-Subproject commit 2e5302ad477c8d96148794a2d9f9e385ea46a82d
+Subproject commit 40aa3fdca0ede895ed6c8f2676b45174ae6ae6b4
diff --git a/server/src/window/candidate_window.cpp b/server/src/window/candidate_window.cpp
index b496cfb8..14ffe06e 100644
--- a/server/src/window/candidate_window.cpp
+++ b/server/src/window/candidate_window.cpp
@@ -235,6 +235,13 @@ LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
         break;
     }
 
+    /* Clear dictionary buffer cache */
+    case WM_USER + 100: {
+        g_dictQuery->reset_cache();
+        OutputDebugString(fmt::format(L"Cleared dictionary buffer cache.").c_str());
+        break;
+    }
+
     default: {
         return DefWindowProc(hwnd, message, wParam, lParam);
     }
diff --git a/server/src/window/candidate_window.h b/server/src/window/candidate_window.h
index 4f1b83b1..22fedab5 100644
--- a/server/src/window/candidate_window.h
+++ b/server/src/window/candidate_window.h
@@ -2,9 +2,9 @@
 
 #include <windows.h>
 
-inline WCHAR szWindowClass[] = L"global_candidate_window";
-inline WCHAR szTitle[] = L"Global Candidate Window";
-inline WCHAR lpWindowName[] = L"fanycandidatewindow";
+inline WCHAR szWindowClass[] = L"metasequoiaime_candidate_window";
+inline WCHAR szTitle[] = L"MetasequoiaIme Candidate Window";
+inline WCHAR lpWindowName[] = L"metaseuqoiaimecandidatewindow";
 
 LRESULT RegisterCandidateWindowMessage();
 LRESULT RegisterCandidateWindowClass(WNDCLASSEX &, HINSTANCE);