diff --git a/module/language/cps/utils.scm b/module/language/cps/utils.scm
index f9092d0b3..1f09fe7c2 100644
--- a/module/language/cps/utils.scm
+++ b/module/language/cps/utils.scm
@@ -405,7 +405,7 @@ by a label, respectively."
       word-ref word-ref/immediate
       untag-char
       vector-length vtable-size bv-length
-      string-length string-ref
+      string-length string-utf8-length string-ref
       symbol-hash)
      '(u64))
     ((untag-fixnum