diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
index 4219f1fb6..5fc41979e 100644
--- a/grub-core/disk/cryptodisk.c
+++ b/grub-core/disk/cryptodisk.c
@@ -1405,7 +1405,11 @@ grub_cryptodisk_clear_key_cache (struct grub_cryptomount_args *cargs)
     return;
 
   for (i = 0; cargs->protectors[i]; i++)
-    grub_free (cargs->key_cache[i].key);
+    {
+      if (cargs->key_cache[i].key)
+	grub_memset (cargs->key_cache[i].key, 0, cargs->key_cache[i].key_len);
+      grub_free (cargs->key_cache[i].key);
+    }
 
   grub_free (cargs->key_cache);
 }