diff --git a/alloca.c b/alloca.c
index 16f19a27..367b7fe0 100644
--- a/alloca.c
+++ b/alloca.c
@@ -25,7 +25,10 @@
 #include "config.h"
 #endif
 
-/* If compiling with GCC, this file's not needed.  */
+/* If compiling with GCC 2, this file's not needed.  */
+#if defined (__GNUC__) && __GNUC__ >= 2
+/* If someone has defined alloca as a macro,
+   there must be some other way alloca is supposed to work.  */
 #ifndef alloca
 
 #ifdef emacs
@@ -473,3 +476,4 @@ i00afunc (long address)
 #endif /* CRAY */
 
 #endif /* no alloca */
+#endif /* not GCC version 2 */