diff --git a/src/conflicts.c b/src/conflicts.c
index 4ed9dea7..03dc1cf9 100644
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -29,7 +29,8 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #include "state.h"
 
 
-#ifdef __GNUC__
+#ifndef __GNUC__
+#undef alloca
 #define alloca __builtin_alloca
 #else
 #ifdef HAVE_ALLOCA_H