diff --git a/session.go b/session.go
index 5bcac1e..4ccb881 100644
--- a/session.go
+++ b/session.go
@@ -45,7 +45,7 @@
 	pendingDuration  = 3e9
 	defaultQLen      = 1024
 	maxIovecNum      = 10
-	maxWheelTimeSpan = 900e9 // 900s, 15 minute
+	MaxWheelTimeSpan = 900e9 // 900s, 15 minute
 
 	defaultSessionName    = "session"
 	defaultTCPSessionName = "tcp-session"
@@ -65,7 +65,7 @@
 
 func init() {
 	span := 100e6 // 100ms
-	buckets := maxWheelTimeSpan / span
+	buckets := MaxWheelTimeSpan / span
 	wheel = gxtime.NewWheel(time.Duration(span), int(buckets)) // wheel longest span is 15 minute
 }