diff --git a/src/pki_mbedcrypto.c b/src/pki_mbedcrypto.c
index 821194b9..628ab6ef 100644
--- a/src/pki_mbedcrypto.c
+++ b/src/pki_mbedcrypto.c
@@ -1075,7 +1075,7 @@ ssh_string pki_key_to_blob(const ssh_key key, enum ssh_key_e type)
 
             if (d == NULL) {
                 SSH_BUFFER_FREE(buffer);
-                return NULL;
+                goto out;
             }
 
             rc = ssh_buffer_add_ssh_string(buffer, d);