diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 02ce2058c14b..f26a8415172a 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -32,8 +32,6 @@
 #include <linux/psi.h>
 #include "blk.h"
 
-#define MAX_KEY_LEN 100
-
 /*
  * blkcg_pol_mutex protects blkcg_policy[] and policy [de]activation.
  * blkcg_pol_register_mutex nests outside of it and synchronizes entire