diff --git a/components/ideintf/propeditutils.pp b/components/ideintf/propeditutils.pp
index 803a838a0e..9a708231c4 100644
--- a/components/ideintf/propeditutils.pp
+++ b/components/ideintf/propeditutils.pp
@@ -81,6 +81,7 @@ type
 
 procedure RegisterGetLookupRoot(const OnGetLookupRoot: TGetLookupRoot);
 procedure UnregisterGetLookupRoot(const OnGetLookupRoot: TGetLookupRoot);
+function StrToBoolOI(S: string): Boolean;
 
 implementation
 
@@ -125,6 +126,15 @@ begin
   GetLookupRoots.Remove(OnGetLookupRoot);
 end;
 
+function StrToBoolOI(S: string): Boolean;
+// Like StrToBool but accepts also '(False)' and '(True)'.
+begin
+  if S = '' then Exit(False);
+  if (Length(S) > 2) and (S[1] = '(') and (S[Length(S)] = ')') then
+    S := Copy(S, 2, Length(S)-2);
+  Result := StrToBool(S);
+end;
+
 { TPersistentSelectionList }
 
 function TPersistentSelectionList.Add(APersistent: TPersistent): integer;
diff --git a/designer/designer.pp b/designer/designer.pp
index d363facf67..20429b7056 100644
--- a/designer/designer.pp
+++ b/designer/designer.pp
@@ -1330,7 +1330,7 @@ procedure TDesigner.ExecuteUndoItem(IsActUndo: boolean);
           tkFloat:
             SetFloatProp(tmpObj, fieldName, StrToFloat(tmpStr));
           tkBool:
-            SetOrdProp(tmpObj, FUndoList[FUndoCurr].fieldName, Integer(StrToBool(tmpStr)));
+            SetOrdProp(tmpObj, FUndoList[FUndoCurr].fieldName, Integer(StrToBoolOI(tmpStr)));
           tkString, tkLString, tkAString, tkUString, tkWString:
             SetStrProp(tmpObj, fieldName, tmpStr);
           tkSet: