diff --git a/acconfig.h b/acconfig.h
index 1e1bb19c..4987eff1 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -10,6 +10,7 @@
 #undef HAVE_PL_PERL
 #undef HAVE_STATIC_PERL
 #undef HAVE_GMODULE
+#undef HAVE_GC
 #undef WANT_BIG5
 
 /* macros/curses checks */