diff --git a/test/big.c b/test/big.c
index fc51e6ef1b..58e7fbc80a 100644
--- a/test/big.c
+++ b/test/big.c
@@ -33,8 +33,10 @@
 #define GB8LL		((unsigned long long)8*1024*1024*1024)
 #elif SIZEOF___INT64 > SIZEOF_LONG
 #define GB8LL		((unsigned __int64)8*1024*1024*1024)
+#elif SIZEOF_LONG >= 8
+#define GB8LL		((unsigned long)8*1024*1024*1024)
 #else
-#define GB8LL		((long)1)
+#define GB8LL		((unsigned long)0)	/* can not do the test */
 #endif
 
 static hsize_t
@@ -135,6 +137,10 @@ enough_room(void)
     size_t	i, size = (size_t)1 << 30;
     char	name[32];
 
+    /* verify if this machine supports 8GB sizes */
+    if (GB8LL==0)
+	goto done;
+
     /* Initialize file descriptors */
     for (i=0; i<NELMTS(fd); i++) fd[i] = -1;