diff --git a/extra/io/launcher/launcher.factor b/extra/io/launcher/launcher.factor
index 7044004218..4a6bbf46fb 100755
--- a/extra/io/launcher/launcher.factor
+++ b/extra/io/launcher/launcher.factor
@@ -2,7 +2,7 @@
 ! See http://factorcode.org/license.txt for BSD license.
 USING: io io.backend system kernel namespaces strings hashtables
 sequences assocs combinators vocabs.loader init threads
-continuations ;
+continuations math ;
 IN: io.launcher
 
 ! Non-blocking process exit notification facility