diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index d5897dc..37f5027 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -6,7 +6,7 @@ jobs:
   unit-benchmark-test:
     strategy:
       matrix:
-        go: [ 1.21.1 ]
+        go: [ 1.20.1 ]
         os: [ X64, ARM64 ]
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/v2/example/go.mod b/v2/example/go.mod
index 98a2eea..746bec6 100644
--- a/v2/example/go.mod
+++ b/v2/example/go.mod
@@ -1,8 +1,6 @@
 module example
 
-go 1.21
-
-toolchain go1.21.1
+go 1.19
 
 require (
 	github.com/cloudwego/kitex v0.8.0
diff --git a/v2/example/go.sum b/v2/example/go.sum
index 00b308f..70e6635 100644
--- a/v2/example/go.sum
+++ b/v2/example/go.sum
@@ -287,7 +287,6 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
-github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/mattn/go-isatty v0.0.13/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
@@ -397,7 +396,6 @@ go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.uber.org/atomic v1.11.0 h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE=
 go.uber.org/atomic v1.11.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
 go.uber.org/goleak v1.2.0 h1:xqgm/S+aQvhWFTtR0XK3Jvg7z8kGV8P4X14IzwN3Eqk=
-go.uber.org/goleak v1.2.0/go.mod h1:XJYK+MuIchqpmGmUSAzotztawfKvYLUIgg7guXrwVUo=
 go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
 go.uber.org/multierr v1.11.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
 go.uber.org/zap v1.26.0 h1:sI7k6L95XOKS281NhVKOFCUNIvv9e0w4BF8N3u+tCRo=
diff --git a/v2/nacos/nacos_test.go b/v2/nacos/nacos_test.go
index 984e573..a8d3717 100644
--- a/v2/nacos/nacos_test.go
+++ b/v2/nacos/nacos_test.go
@@ -29,7 +29,6 @@ type fakeNacos struct {
 }
 
 func (fn *fakeNacos) CloseClient() {
-	return
 }
 
 func (fn *fakeNacos) GetConfig(param vo.ConfigParam) (string, error) {