diff --git a/components/codetools/sourcechanger.pas b/components/codetools/sourcechanger.pas
index 5f49ec304d..ca2da85341 100644
--- a/components/codetools/sourcechanger.pas
+++ b/components/codetools/sourcechanger.pas
@@ -39,7 +39,7 @@ unit SourceChanger;
 
 interface
 
-{off $DEFINE CTDEBUG}
+{$DEFINE CTDEBUG}
 
 uses
   Classes, SysUtils, FileProcs, CodeToolsStrConsts, CodeCache, BasicCodeTools,
diff --git a/converter/convcodetool.pas b/converter/convcodetool.pas
index d747981066..fb18f615a6 100644
--- a/converter/convcodetool.pas
+++ b/converter/convcodetool.pas
@@ -75,15 +75,17 @@ begin
   try
     fSrcCache.BeginUpdate;
     try
+      // these changes can be applied together without rescan
       if not AddModeDelphiDirective then exit;
       if not RemoveDFMResourceDirective then exit;
       if not LowerCaseMainResourceDirective then exit;
       if not AddLRSIncludeDirective then exit;
-      if not ConvertUsedUnits then exit;
       if not fSrcCache.Apply then exit;
     finally
       fSrcCache.EndUpdate;
     end;
+    if not ConvertUsedUnits then exit;
+    if not fSrcCache.Apply then exit;
     Result:=mrOK;
   except
     Result:=JumpToCodetoolErrorAndAskToAbort(fAsk);
@@ -130,12 +132,15 @@ begin
     begin
       exit;
     end;
+    if not fSrcCache.Apply then exit;
   end;
   if fAddLRSCode then
+  begin
     if not fCodeTool.AddUnitToMainUsesSection('LResources','',fSrcCache) then
     begin
       exit;
     end;
+  end;
   if not fCodeTool.RemoveUnitFromAllUsesSections('VARIANTS',fSrcCache) then
   begin
     exit;