diff --git a/extra/update/update.factor b/extra/update/update.factor
index 9b10ea746f..1d25a9792e 100644
--- a/extra/update/update.factor
+++ b/extra/update/update.factor
@@ -22,7 +22,8 @@ IN: update
 ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
 : remote-clean-image ( -- url )
-  "http://factorcode.org/images/clean/" my-boot-image-name append ;
+  { "http://factorcode.org/images/clean/" platform "/" my-boot-image-name }
+  to-string ;
 
 : download-clean-image ( -- ) remote-clean-image download ;