diff --git a/core/group_chat.go b/core/group_chat.go
index f659eaa..26ab557 100644
--- a/core/group_chat.go
+++ b/core/group_chat.go
@@ -44,6 +44,10 @@ var increaseSizeScript = `
 	return {newsize, newseq}
 `
 var decreaseSizeScript = `
+	local exists = redis.call("EXISTS", "_m_"..KEYS[1])
+	if exists == 0 then
+		return {err = "not target"} 
+	end
 	local newseq = redis.call("HINCRBY", KEYS[1], "seq", 1)
 	local newsize = redis.call("HINCRBY", KEYS[1], "size", -1)
 	redis.call("HDEL", "_m_"..KEYS[1], KEYS[2])
diff --git a/go.mod b/go.mod
index 3d26a50..e96a392 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,7 @@ go 1.20
 require (
 	github.com/go-redis/redis/v8 v8.11.5
 	go.mongodb.org/mongo-driver v1.11.7
-	repositories.action2quare.com/ayo/gocommon v0.0.0-20230719073844-112e037f4d4e
+	repositories.action2quare.com/ayo/gocommon v0.0.0-20230727125528-8ea2a698ce38
 )
 
 require (
diff --git a/go.sum b/go.sum
index 596dff2..4aa118a 100644
--- a/go.sum
+++ b/go.sum
@@ -136,3 +136,7 @@ repositories.action2quare.com/ayo/gocommon v0.0.0-20230719003525-e0e911f9e7da h1
 repositories.action2quare.com/ayo/gocommon v0.0.0-20230719003525-e0e911f9e7da/go.mod h1:PdpZ16O1czKKxCxn+0AFNaEX/0kssYwC3G8jR0V7ybw=
 repositories.action2quare.com/ayo/gocommon v0.0.0-20230719073844-112e037f4d4e h1:WoQVMfkti9XZesqlZfU0Lh7Luib4Y7pOKU2YExNvfmo=
 repositories.action2quare.com/ayo/gocommon v0.0.0-20230719073844-112e037f4d4e/go.mod h1:PdpZ16O1czKKxCxn+0AFNaEX/0kssYwC3G8jR0V7ybw=
+repositories.action2quare.com/ayo/gocommon v0.0.0-20230727123118-854084d819e0 h1:WyVWL/4LoNgQlbiambJr1Dq/Px/Qe8lt7UP5jplTrz8=
+repositories.action2quare.com/ayo/gocommon v0.0.0-20230727123118-854084d819e0/go.mod h1:PdpZ16O1czKKxCxn+0AFNaEX/0kssYwC3G8jR0V7ybw=
+repositories.action2quare.com/ayo/gocommon v0.0.0-20230727125528-8ea2a698ce38 h1:P/Cg82LyNHUBByhRRtxAKXaalWSbYOvYhBzfqXlRXHY=
+repositories.action2quare.com/ayo/gocommon v0.0.0-20230727125528-8ea2a698ce38/go.mod h1:PdpZ16O1czKKxCxn+0AFNaEX/0kssYwC3G8jR0V7ybw=