diff --git a/include/dm/test.h b/include/dm/test.h
index 6ac6672..c5a9610 100644
--- a/include/dm/test.h
+++ b/include/dm/test.h
@@ -6,6 +6,8 @@
 #ifndef __DM_TEST_H
 #define __DM_TEST_H
 
+struct udevice;
+
 /**
  * struct dm_test_cdata - configuration data for test instance
  *