diff --git a/migration/options.c b/migration/options.c
index 6ba7ff65a379e5bed488df699d5e80c0b2072d55..136a8575df12899ed0e7120ae63a19fd81cb3d17 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -865,8 +865,10 @@ uint64_t migrate_max_postcopy_bandwidth(void)
 MigMode migrate_mode(void)
 {
     MigrationState *s = migrate_get_current();
+    MigMode mode = s->parameters.mode;
 
-    return s->parameters.mode;
+    assert(mode >= 0 && mode < MIG_MODE__MAX);
+    return mode;
 }
 
 int migrate_hdbss_buffer_size(void)