diff --git a/src/conf/domain_event.c b/src/conf/domain_event.c
index 644f6eb595..900d8f745e 100644
--- a/src/conf/domain_event.c
+++ b/src/conf/domain_event.c
@@ -1935,8 +1935,12 @@ virDomainQemuMonitorEventNew(int id,
         return NULL;
 
     /* event is mandatory, details are optional */
-    if (!event)
+    if (!event) {
+        virReportError(VIR_ERR_INVALID_ARG,
+                       _("unexpected event=NULL name=%s uuid=%s details=%s"),
+                       name, uuidstr, NULLSTR(details));
         goto error;
+    }
 
     ev->event = g_strdup(event);
     ev->seconds = seconds;
diff --git a/src/conf/domain_event.h b/src/conf/domain_event.h
index d1cfb81d62..0a4bce3d04 100644
--- a/src/conf/domain_event.h
+++ b/src/conf/domain_event.h
@@ -321,4 +321,4 @@ virDomainQemuMonitorEventNew(int id,
                              long long seconds,
                              unsigned int micros,
                              const char *details)
-    ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3) ATTRIBUTE_NONNULL(4);
+    ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);