diff --git a/src/eval.c b/src/eval.c
index 2e3d9fd..bf0c303 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -5866,7 +5866,7 @@
     return item1 == NULL && item2 == NULL;
 }
 
-#if defined(FEAT_PYTHON) || defined(PROTO)
+#if defined(FEAT_PYTHON) || defined(FEAT_MZSCHEME) || defined(PROTO)
 /*
  * Return the dictitem that an entry in a hashtable points to.
  */