diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h
index 27d5fe4..ae013b0 100644
--- a/tools/testing/radix-tree/linux/kernel.h
+++ b/tools/testing/radix-tree/linux/kernel.h
@@ -13,6 +13,7 @@
 
 #define BUG_ON(expr)	assert(!(expr))
 #define __init
+#define __must_check
 #define panic(expr)
 #define printk printf
 #define __force