diff --git a/storage/myisam/mi_open.c b/storage/myisam/mi_open.c
index 86cf25b59ef..5951aef6d4f 100644
--- a/storage/myisam/mi_open.c
+++ b/storage/myisam/mi_open.c
@@ -232,7 +232,8 @@ MI_INFO *mi_open(const char *name, int mode, uint open_flags)
     }
 
     /* sanity check */
-    if (share->base.keystart > 65535 || share->base.rec_reflength > 8)
+    if (share->base.keystart > 65535 || 
+        share->base.rec_reflength > 8 || share->base.key_reflength > 7) 
     {
       my_errno=HA_ERR_CRASHED;
       goto err;