diff --git a/converter/missingpropertiesdlg.pas b/converter/missingpropertiesdlg.pas
index 8bf3536a10..ba3d3b5052 100644
--- a/converter/missingpropertiesdlg.pas
+++ b/converter/missingpropertiesdlg.pas
@@ -490,8 +490,10 @@ begin
       if ClassUnitInfo<>nil then
         NeededUnitName:=ClassUnitInfo.Unit_Name;
     end;
-    if NeededUnitName<>'' then
-      fUsedUnitsTool.AddUnitIfNeeded(NeededUnitName);
+    if NeededUnitName<>'' then begin
+      fUsedUnitsTool.AddUnitImmediately(NeededUnitName);
+      Result:=mrRetry;  // Caller must check LFM validity again
+    end;
   end;
 end;
 
@@ -520,28 +522,29 @@ begin
   finally
     ConvTool.Free;
   end;
-  LoopCount:=0;
+  LoopCount:=0;    // Prevent possible eternal loops with a counter
   repeat
-    if not fLFMTree.ParseIfNeeded then exit;
+    repeat
+      if not fLFMTree.ParseIfNeeded then exit;
+      if CodeToolBoss.CheckLFM(fPascalBuffer, fLFMBuffer, fLFMTree,
+          fRootMustBeClassInUnit, fRootMustBeClassInIntf, fObjectsMustExist) then
+        Result:=mrOk
+      else                     // Rename/remove properties and types interactively.
+        Result:=ShowConvertLFMWizard;  // Can return mrRetry.
+      Inc(LoopCount);                  // Increment counter in inner loop
+    until Result in [mrOK, mrCancel];
+
+    // Check for missing object types and add units as needed.
+    if not fLFMTree.ParseIfNeeded then
+      Exit(mrCancel);
     if CodeToolBoss.CheckLFM(fPascalBuffer, fLFMBuffer, fLFMTree,
         fRootMustBeClassInUnit, fRootMustBeClassInIntf, fObjectsMustExist) then
       Result:=mrOk
-    else                     // Rename/remove properties and types interactively.
-      Result:=ShowConvertLFMWizard;  // Can return mrRetry.
-    Inc(LoopCount);
-  until (Result in [mrOK, mrCancel]) or (LoopCount=20);
-
-  // Check for missing object types and add units as needed.
-  if not fLFMTree.ParseIfNeeded then
-    Exit(mrCancel);
-  if CodeToolBoss.CheckLFM(fPascalBuffer, fLFMBuffer, fLFMTree,
-      fRootMustBeClassInUnit, fRootMustBeClassInIntf, fObjectsMustExist) then
-    Result:=mrOk
-  else begin
-    Result:=FindAndFixMissingComponentClasses;
-    if Result = mrCancel then  // Returns mrCancel when nothing was done.
-      Result := mrOK;
-  end;
+    else begin
+      Result:=FindAndFixMissingComponentClasses; // Can return mrRetry.
+    end;
+    Inc(LoopCount);                    // Increment also in outer loop
+  until (Result in [mrOK, mrAbort]) or (LoopCount=30);
 
   // Fix top offsets of some components in visual containers
   if (Result=mrOK) and (fSettings.CoordOffsMode=rsEnabled) then begin
diff --git a/converter/usedunits.pas b/converter/usedunits.pas
index f4a20f2709..6042eff59f 100644
--- a/converter/usedunits.pas
+++ b/converter/usedunits.pas
@@ -128,6 +128,7 @@ type
     function ConvertUsed: TModalResult;
     function Remove(aUnit: string): TModalResult;
     procedure MoveMissingToComment(aAllCommentedUnits: TStrings);
+    function AddUnitImmediately(aUnitName: string): Boolean;
     procedure AddUnitIfNeeded(aUnitName: string);
     function AddThreadSupport: TModalResult;
   public
@@ -689,6 +690,15 @@ begin
   fImplUsedUnits.fMissingUnits.Clear;
 end;
 
+function TUsedUnitsTool.AddUnitImmediately(aUnitName: string): Boolean;
+begin
+  with fCTLink, fMainUsedUnits do begin
+    Result:=CodeTool.AddUnitToSpecificUsesSection(fUsesSection, aUnitName, '', SrcCache);
+    if not Result then exit;
+    Result:=SrcCache.Apply;
+  end;
+end;
+
 procedure TUsedUnitsTool.AddUnitIfNeeded(aUnitName: string);
 
   // Return True if the rename (target) value contains aUnitName.
diff --git a/ide/checklfmdlg.pas b/ide/checklfmdlg.pas
index a69aa2b542..a2b8b78e07 100644
--- a/ide/checklfmdlg.pas
+++ b/ide/checklfmdlg.pas
@@ -396,12 +396,15 @@ begin
   if not CheckUnit then exit;
   if CodeToolBoss.CheckLFM(fPascalBuffer,fLFMBuffer,fLFMTree,
                fRootMustBeClassInUnit,fRootMustBeClassInIntf,fObjectsMustExist)
-  then begin
-    Result:=mrOk;
-    exit;
-  end;
+  then
+    exit(mrOk);
   Result:=FindAndFixMissingComponentClasses;
-  if Result in [mrAbort,mrOk] then exit;
+  if Result=mrAbort then exit;
+  // check LFM again
+  if CodeToolBoss.CheckLFM(fPascalBuffer,fLFMBuffer,fLFMTree,
+             fRootMustBeClassInUnit,fRootMustBeClassInIntf,fObjectsMustExist)
+  then
+    exit(mrOk);
   WriteLFMErrors;
   Result:=ShowRepairLFMWizard;
 end;
@@ -463,7 +466,7 @@ var
   RegComp: TRegisteredComponent;
   i: Integer;
 begin
-  Result:=mrCancel;
+  Result:=mrOK;
   MissingObjectTypes:=TStringList.Create;
   try
     // collect all missing object types
@@ -496,15 +499,6 @@ begin
   // add units for the missing object types with registered component classes
   Result:=PackageEditingInterface.AddUnitDependenciesForComponentClasses(
        fPascalBuffer.Filename, aMissingTypes);
-  if Result<>mrOk then exit;
-  // check LFM again
-  if CodeToolBoss.CheckLFM(fPascalBuffer,fLFMBuffer,fLFMTree,
-             fRootMustBeClassInUnit,fRootMustBeClassInIntf,fObjectsMustExist)
-  then begin
-    Result:=mrOk;
-  end else begin
-    Result:=mrCancel;
-  end;
 end;
 
 function TLFMChecker.CheckUnit: boolean;