diff --git a/unit_test/test_spdm_requester/encap_key_update.c b/unit_test/test_spdm_requester/encap_key_update.c
index 3d352697638..8ab95e1e616 100644
--- a/unit_test/test_spdm_requester/encap_key_update.c
+++ b/unit_test/test_spdm_requester/encap_key_update.c
@@ -414,9 +414,9 @@ void test_libspdm_requester_encap_key_update_case4(void **state)
 
     /*no capabilities*/
     spdm_context->connection_info.capability.flags &=
-        !SPDM_GET_CAPABILITIES_RESPONSE_FLAGS_KEY_UPD_CAP;
+        ~SPDM_GET_CAPABILITIES_RESPONSE_FLAGS_KEY_UPD_CAP;
     spdm_context->local_context.capability.flags &=
-        !SPDM_GET_CAPABILITIES_REQUEST_FLAGS_KEY_UPD_CAP;
+        ~SPDM_GET_CAPABILITIES_REQUEST_FLAGS_KEY_UPD_CAP;
 
     session_info = &spdm_context->session_info[0];
     secured_message_context = session_info->secured_message_context;