diff --git a/trie/database.go b/trie/database.go
index 9a4c05d154..cd89ae4283 100644
--- a/trie/database.go
+++ b/trie/database.go
@@ -55,7 +55,7 @@ var (
 var secureKeyPrefix = []byte("secure-key-")
 
 // secureKeyLength is the length of the above prefix + 32byte hash.
-const secureKeyLength = 11 + 32
+const secureKeyLength = len(secureKeyPrefix) + 32
 
 // Database is an intermediate write layer between the trie data structures and
 // the disk database. The aim is to accumulate trie writes in-memory and only