diff --git a/tools/testing/radix-tree/tag_check.c b/tools/testing/radix-tree/tag_check.c
index b7447ce..b0ac057 100644
--- a/tools/testing/radix-tree/tag_check.c
+++ b/tools/testing/radix-tree/tag_check.c
@@ -122,7 +122,7 @@
 	NODE_TAGGED = 2,
 };
 
-#define THRASH_SIZE		1000 * 1000
+#define THRASH_SIZE		(1000 * 1000)
 #define N 127
 #define BATCH	33