diff --git a/basis/libc/libc.factor b/basis/libc/libc.factor
index 4a887e695f..27d7555d67 100644
--- a/basis/libc/libc.factor
+++ b/basis/libc/libc.factor
@@ -99,3 +99,4 @@ PRIVATE>
     size_t "libc" "strlen" { c-string } alien-invoke ;
 
 DESTRUCTOR: free
+DESTRUCTOR: (free)