diff --git a/tests/webtbs/tw4013.pp b/tests/webtbs/tw4013.pp
index cd34b1721a..96f1a29e5e 100644
--- a/tests/webtbs/tw4013.pp
+++ b/tests/webtbs/tw4013.pp
@@ -4,7 +4,7 @@
 PROGRAM Test;
 
 uses
-  variants;
+  math;
 
 BEGIN