diff --git a/src/daemon/https/tls/gnutls_pk.c b/src/daemon/https/tls/gnutls_pk.c
index 527ab8ab..20f17951 100644
--- a/src/daemon/https/tls/gnutls_pk.c
+++ b/src/daemon/https/tls/gnutls_pk.c
@@ -320,7 +320,7 @@ mhd_gtls_pkcs1_rsa_decrypt (gnutls_datum_t * plaintext,
     default:
       gnutls_assert ();
       gnutls_afree (edata);
-      break;
+      return GNUTLS_E_DECRYPTION_FAILED;
     }
   i++;