diff --git a/net/ceph/crypto.h b/net/ceph/crypto.h
index d149822..2e9cab0 100644
--- a/net/ceph/crypto.h
+++ b/net/ceph/crypto.h
@@ -16,8 +16,10 @@
 
 static inline void ceph_crypto_key_destroy(struct ceph_crypto_key *key)
 {
-	if (key)
+	if (key) {
 		kfree(key->key);
+		key->key = NULL;
+	}
 }
 
 int ceph_crypto_key_clone(struct ceph_crypto_key *dst,