diff --git a/tests/webtbs/tw37301.pp b/tests/webtbs/tw37301.pp
index 43c20f939d..3d5cb12ec6 100644
--- a/tests/webtbs/tw37301.pp
+++ b/tests/webtbs/tw37301.pp
@@ -10,4 +10,7 @@ begin
   b := 0;
   w := abs(i-b);
   WriteLn(w);
+  if w<>53 then
+    halt(1);
+  Writeln('ok');
 end.