diff --git a/storage/conformance/transactions.go b/storage/conformance/transactions.go
index 2fc6755b..1d4011a4 100644
--- a/storage/conformance/transactions.go
+++ b/storage/conformance/transactions.go
@@ -75,6 +75,7 @@ func testAuthRequestConcurrentUpdate(t *testing.T, s storage.Storage) {
 			EmailVerified: true,
 			Groups:        []string{"a", "b"},
 		},
+		HMACKey: []byte("hmac_key"),
 	}
 
 	if err := s.CreateAuthRequest(a); err != nil {