diff --git a/collects/mzlib/private/match/match-helper.ss b/collects/mzlib/private/match/match-helper.ss
index ff93d82dfb..76cda39780 100644
--- a/collects/mzlib/private/match/match-helper.ss
+++ b/collects/mzlib/private/match/match-helper.ss
@@ -29,7 +29,8 @@
      (boolean? v)
      (char? v)
      (number? v)
-     (keyword? v)))
+     (keyword? v)
+     (bytes? v)))
   
   
   ;;!(function symbol-append