diff --git a/core/io/pathnames/pathnames.factor b/core/io/pathnames/pathnames.factor
index 5fe3dbf16c..2d382e49d1 100644
--- a/core/io/pathnames/pathnames.factor
+++ b/core/io/pathnames/pathnames.factor
@@ -89,7 +89,7 @@ PRIVATE>
 
 : append-relative-path ( path1 path2 -- path )
     [ trim-tail-separators ]
-    [ trim-head-separators ] bi* path-separator glue ;
+    [ trim-head-separators ] bi* "/" glue ;
 
 : append-path ( path1 path2 -- path )
     {