diff --git a/components/codetools/codecache.pas b/components/codetools/codecache.pas
index fd008f2972..d826ac7b5e 100644
--- a/components/codetools/codecache.pas
+++ b/components/codetools/codecache.pas
@@ -749,9 +749,10 @@ end;
 function TCodeCache.CreateFile(const AFilename: string): TCodeBuffer;
 begin
   Result:=FindFile(AFileName);
-  if Result<>nil then begin
-    Result.Clear;
-  end else begin
+  // Create a new buffer also when only char case differs in names.
+  if (Result<>nil) and (Result.Filename=AFilename) then
+    Result.Clear
+  else begin
     Result:=TCodeBuffer.Create;
     Result.FileName:=AFileName;
     FItems.Add(Result);
diff --git a/ide/sourcefilemanager.pas b/ide/sourcefilemanager.pas
index 55a6b361f7..849b7e478f 100644
--- a/ide/sourcefilemanager.pas
+++ b/ide/sourcefilemanager.pas
@@ -6024,7 +6024,7 @@ begin
   // check if file is already lowercase (or it does not matter in current OS)
   OldShortFilename:=ExtractFilename(OldFilename);
   NewShortFilename:=lowercase(OldShortFilename);
-  if CompareFilenames(OldShortFilename,NewShortFilename)=0 then exit;
+  if OldShortFilename=NewShortFilename then exit;
   // create new filename
   NewFilename:=ExtractFilePath(OldFilename)+NewShortFilename;