diff --git a/basis/urls/encoding/encoding.factor b/basis/urls/encoding/encoding.factor
index a5f5d62bfc..8e11dec431 100644
--- a/basis/urls/encoding/encoding.factor
+++ b/basis/urls/encoding/encoding.factor
@@ -37,7 +37,7 @@ IN: urls.encoding
 
 : push-utf8 ( ch -- )
     1string utf8 encode
-    [ CHAR: % , >hex 2 CHAR: 0 pad-head % ] each ;
+    [ CHAR: % , >hex >upper 2 CHAR: 0 pad-head % ] each ;
 
 PRIVATE>