diff --git a/mysys/my_bitmap.c b/mysys/my_bitmap.c
index b4990816b560296f8563c240f1369486c3404604..a80aafd560592da4ab4193be2e1263cd36c9e794 100644
--- a/mysys/my_bitmap.c
+++ b/mysys/my_bitmap.c
@@ -29,7 +29,8 @@
 
 my_bool bitmap_init(MY_BITMAP *map, uint bitmap_size)
 {
-  if (!(map->bitmap=(uchar*) my_malloc((bitmap_size+7)/8,MYF(MY_WME))))
+  if (!(map->bitmap=(uchar*) my_malloc((bitmap_size+7)/8,
+				       MYF(MY_WME | MY_ZEROFILL))))
     return 1;
   dbug_assert(bitmap_size != ~(uint) 0);
 #ifdef THREAD