diff --git a/src/modules/module-device-manager.c b/src/modules/module-device-manager.c
index 2ce4c7892..e11921dae 100644
--- a/src/modules/module-device-manager.c
+++ b/src/modules/module-device-manager.c
@@ -576,7 +576,7 @@ static void update_highest_priority_device_indexes(struct userdata *u, const cha
             struct entry *e;
 
             name = pa_xstrndup(key.data, key.size);
-            device_name = get_name(name, prefix);
+            pa_assert_se(device_name = get_name(name, prefix));
 
             if ((e = entry_read(u, name))) {
                 for (uint32_t i = 0; i < NUM_ROLES; ++i) {