diff --git a/autoload/youcompleteme.vim b/autoload/youcompleteme.vim
index 2fed7eed..1f8a6a15 100644
--- a/autoload/youcompleteme.vim
+++ b/autoload/youcompleteme.vim
@@ -567,8 +567,7 @@ endfunction
 
 function! s:UpdateDiagnosticNotifications()
   let should_display_diagnostics = g:ycm_show_diagnostics_ui &&
-        \ s:DiagnosticUiSupportedForCurrentFiletype() &&
-        \ pyeval( 'ycm_state.NativeFiletypeCompletionUsable()' )
+        \ s:DiagnosticUiSupportedForCurrentFiletype()
 
   if !should_display_diagnostics
     return
diff --git a/python/ycm/youcompleteme.py b/python/ycm/youcompleteme.py
index 58cdb2e1..e4700bd1 100644
--- a/python/ycm/youcompleteme.py
+++ b/python/ycm/youcompleteme.py
@@ -299,7 +299,8 @@ class YouCompleteMe( object ):
 
 
   def UpdateDiagnosticInterface( self ):
-    if not self.DiagnosticsForCurrentFileReady():
+    if ( not self.DiagnosticsForCurrentFileReady() or
+         not self.NativeFiletypeCompletionUsable() ):
       return
     self._diag_interface.UpdateWithNewDiagnostics(
       self.GetDiagnosticsFromStoredRequest() )