diff --git a/bigcache.go b/bigcache.go
index 045d1cf8..0adefed4 100644
--- a/bigcache.go
+++ b/bigcache.go
@@ -32,13 +32,14 @@ type Response struct {
 type RemoveReason uint32
 
 const (
+	_ RemoveReason = iota
 	// Expired means the key is past its LifeWindow.
-	Expired = RemoveReason(1)
+	Expired
 	// NoSpace means the key is the oldest and the cache size was at its maximum when Set was called, or the
 	// entry exceeded the maximum shard size.
-	NoSpace = RemoveReason(2)
+	NoSpace
 	// Deleted means Delete was called and this key was removed as a result.
-	Deleted = RemoveReason(3)
+	Deleted
 )
 
 // NewBigCache initialize new instance of BigCache