diff --git a/basis/images/images.factor b/basis/images/images.factor
index 430f5bee5e..2d90faf9ad 100644
--- a/basis/images/images.factor
+++ b/basis/images/images.factor
@@ -70,7 +70,7 @@ TUPLE: image
 : <image> ( -- image ) image new ; inline
 
 : image-dim ( image -- dim )
-    [ dim>> ] [ 2x?>> ] bi [ [ 2/ ] map ] when ;
+    [ dim>> ] [ 2x?>> ] bi [ [ 2.0 / ] map ] when ;
 
 : has-alpha? ( image -- ? ) component-order>> alpha-channel? ;