diff --git a/core/io/files/files.factor b/core/io/files/files.factor
index 87e927304b..ff265e43b1 100755
--- a/core/io/files/files.factor
+++ b/core/io/files/files.factor
@@ -147,6 +147,9 @@ PRIVATE>
         ] if
     ] unless ;
 
+: file-extension ( filename -- extension )
+    "." last-split1 nip ;
+
 ! File info
 TUPLE: file-info type size permissions modified ;