diff --git a/src/config.h.in b/src/config.h.in
index 1c888f4..f182f7b 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -271,6 +271,9 @@
 /* Define if you want huge features. */
 #undef FEAT_HUGE
 
+/* Define if you want to include the MzScheme interpreter. */
+#undef FEAT_MZSCHEME
+
 /* Define if you want to include the Perl interpreter. */
 #undef FEAT_PERL