diff --git a/tests/test_monitor.cpp b/tests/test_monitor.cpp
index 9788efe0..4af013b1 100644
--- a/tests/test_monitor.cpp
+++ b/tests/test_monitor.cpp
@@ -171,7 +171,7 @@ void test_monitor_versioned_basic (bind_function_t bind_function_,
         event = get_monitor_event_v2 (client_mon, NULL, &client_local_address,
                                       &client_remote_address);
     }
-    TEST_ASSERT_EQUAL (ZMQ_EVENT_CONNECTED, event);
+    TEST_ASSERT_EQUAL_HEX64 (ZMQ_EVENT_CONNECTED, event);
     TEST_ASSERT_EQUAL_STRING (server_endpoint, client_remote_address);
     TEST_ASSERT_EQUAL_STRING_LEN (expected_prefix_, client_local_address,
                                   strlen (expected_prefix_));
@@ -192,11 +192,11 @@ void test_monitor_versioned_basic (bind_function_t bind_function_,
     event = get_monitor_event_v2 (server_mon, NULL, NULL, NULL);
     //  Sometimes the server sees the client closing before it gets closed.
     if (event != ZMQ_EVENT_DISCONNECTED) {
-        TEST_ASSERT_EQUAL_INT (ZMQ_EVENT_CLOSED, event);
+        TEST_ASSERT_EQUAL_HEX64 (ZMQ_EVENT_CLOSED, event);
         event = get_monitor_event_v2 (server_mon, NULL, NULL, NULL);
     }
     if (event != ZMQ_EVENT_DISCONNECTED) {
-        TEST_ASSERT_EQUAL_INT (ZMQ_EVENT_MONITOR_STOPPED, event);
+        TEST_ASSERT_EQUAL_HEX64 (ZMQ_EVENT_MONITOR_STOPPED, event);
     }
     free (client_local_address);
     free (client_remote_address);
diff --git a/tests/testutil_monitoring.hpp b/tests/testutil_monitoring.hpp
index ee2d0a0b..1554391a 100644
--- a/tests/testutil_monitoring.hpp
+++ b/tests/testutil_monitoring.hpp
@@ -306,7 +306,7 @@ void expect_monitor_event_v2 (void *monitor_,
       expected_remote_address_ ? &remote_address : NULL);
     bool failed = false;
     if (event != expected_event_) {
-        fprintf (stderr, "Expected monitor event %lld, but received %lld\n",
+        fprintf (stderr, "Expected monitor event %llx, but received %llx\n",
                  (long long) expected_event_, (long long) event);
         failed = true;
     }