diff --git a/lcl/include/customnotebook.inc b/lcl/include/customnotebook.inc
index 914167cceb..f68d23567a 100644
--- a/lcl/include/customnotebook.inc
+++ b/lcl/include/customnotebook.inc
@@ -318,7 +318,9 @@ begin
         Inc(VisiblePageInd)
       else begin
         if VisiblePageInd < Result then
-          Inc(Result);
+          Inc(Result)
+        else
+          Break;
       end;
     end;
   end