diff --git a/src/lib/libc/stdlib/calloc.c b/src/lib/libc/stdlib/calloc.c
index c53b22b4..c75b256d 100644
--- a/src/lib/libc/stdlib/calloc.c
+++ b/src/lib/libc/stdlib/calloc.c
@@ -32,7 +32,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char *rcsid = "$OpenBSD: calloc.c,v 1.6 2002/07/30 00:11:07 deraadt Exp $";
+static char *rcsid = "$OpenBSD: calloc.c,v 1.7 2002/07/31 09:19:04 deraadt Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <stdlib.h>
@@ -47,7 +47,7 @@ calloc(num, size)
 {
 	register void *p;
 
-	if (SIZE_T_MAX / num < size) {
+	if (num && size && SIZE_T_MAX / num < size) {
 		errno = ENOMEM;
 		return NULL;
 	}