diff --git a/packages/rtl-objpas/src/inc/system.uitypes.pp b/packages/rtl-objpas/src/inc/system.uitypes.pp
index eb099fba8c..75ba4d0e27 100644
--- a/packages/rtl-objpas/src/inc/system.uitypes.pp
+++ b/packages/rtl-objpas/src/inc/system.uitypes.pp
@@ -19,7 +19,7 @@ unit System.UITypes;
 interface
 
 Type  
-    TColor      = Longint;
+    TColor      = -$7FFFFFFF-1..$7FFFFFFF;
     PColor      = ^TColor;
     TColorRef   = Cardinal;
     PColorRef   = ^TColorRef;