diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index b004c21..e6d29cf 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -13,30 +13,10 @@ jobs:
       matrix:
         module: [
           '', 'otlp', 'gcp',
-          'grpc', 'examples/grpc'
-        ]
-        go-version: [ 'stable', 'oldstable' ]
-    name: Test
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-go@v5
-        with:
-          go-version: ${{ matrix.go-version }}
-          cache-dependency-path: "**/go.sum"
-      - name: Race Test
-        run: go test -v -shuffle=on -count=10 -race ./...
-        working-directory: ${{ matrix.module }}
-      - name: Test
-        run: go test -shuffle=on -v ./...
-        working-directory: ${{ matrix.module }}
-  test-http:
-    strategy:
-      matrix:
-        module: [
+          'grpc', 'examples/grpc',
           'http', 'examples/http'
         ]
-        go-version: [ 'stable' ]
+        go-version: [ 'stable', 'oldstable' ]
     name: Test
     runs-on: ubuntu-latest
     steps:
@@ -55,7 +35,7 @@ jobs:
     if: ${{ always() }}
     runs-on: ubuntu-latest
     name: All Tests
-    needs: [test, test-http]
+    needs: test
     steps:
       - name: Check test matrix status
         if: ${{ needs.test.result != 'success' }}
diff --git a/.golangci.yml b/.golangci.yml
index ad140e2..b4a790e 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -16,6 +16,10 @@ linters-settings:
     local-prefixes: github.com/nil-go/nilgo
   gomoddirectives:
     replace-local: true
+  gosec:
+    excludes:
+      # Flags for potentially-unsafe casting of ints, similar problem to globally-disabled G103
+      - G115
   govet:
     enable:
       - shadow
@@ -38,7 +42,7 @@ linters:
     - canonicalheader
     - containedctx
     - contextcheck
-    # copyloopvar
+    - copyloopvar
     - cyclop
     - decorder
     # depguard
@@ -51,7 +55,6 @@ linters:
     - errchkjson
     - errname
     - errorlint
-    - exportloopref
     - exhaustive
     # exhaustruct
     - fatcontext
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1acc3e9..684f2d4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,9 +7,14 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Removed
+
+- Remove support for Golang 1.21 (#122).
+
 ## [0.2.0] - 2024-05-17
 
 ### Added
+
 - Support Open Telemetry with OTLP exporters (#61).
 
 ## [0.1.0] - 2024-05-07
diff --git a/examples/grpc/go.mod b/examples/grpc/go.mod
index 6f28738..bedab55 100644
--- a/examples/grpc/go.mod
+++ b/examples/grpc/go.mod
@@ -1,6 +1,6 @@
 module github.com/nil-go/nilgo/examples/grpc
 
-go 1.21
+go 1.22
 
 require (
 	cloud.google.com/go/compute/metadata v0.3.0
diff --git a/examples/http/cmd/main.go b/examples/http/cmd/main.go
index 7309608..2a1697f 100644
--- a/examples/http/cmd/main.go
+++ b/examples/http/cmd/main.go
@@ -51,18 +51,20 @@ func main() {
 		}
 	})
 	server := &http.Server{
-		Handler: otelhttp.NewHandler(mux, "", otelhttp.WithSpanNameFormatter(func(operation string, r *http.Request) string {
-			if operation != "" {
-				return operation
-			}
+		Handler: otelhttp.NewHandler(mux, "", otelhttp.WithSpanNameFormatter(
+			func(operation string, req *http.Request) string {
+				if operation != "" {
+					return operation
+				}
 
-			method := r.Method
-			if method == "" {
-				method = "GET"
-			}
+				method := req.Method
+				if method == "" {
+					method = "GET"
+				}
 
-			return method + " " + r.URL.Path
-		})),
+				return method + " " + req.URL.Path
+			}),
+		),
 		ReadTimeout: time.Second,
 	}
 	runs = append(runs,
diff --git a/gcp/go.mod b/gcp/go.mod
index 62cf161..4a1bc9f 100644
--- a/gcp/go.mod
+++ b/gcp/go.mod
@@ -1,6 +1,6 @@
 module github.com/nil-go/nilgo/gcp
 
-go 1.21
+go 1.22
 
 require (
 	cloud.google.com/go/compute/metadata v0.5.0
diff --git a/go.mod b/go.mod
index eaf1a71..663e774 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/nil-go/nilgo
 
-go 1.21
+go 1.22
 
 require (
 	go.opentelemetry.io/otel v1.29.0
diff --git a/grpc/go.mod b/grpc/go.mod
index d77574d..23dc133 100644
--- a/grpc/go.mod
+++ b/grpc/go.mod
@@ -1,6 +1,6 @@
 module github.com/nil-go/nilgo/grpc
 
-go 1.21
+go 1.22
 
 require (
 	github.com/nil-go/konf v1.2.2
diff --git a/grpc/internal/buffer_test.go b/grpc/internal/buffer_test.go
index 4474c7d..a0a3bb6 100644
--- a/grpc/internal/buffer_test.go
+++ b/grpc/internal/buffer_test.go
@@ -45,8 +45,6 @@ level=ERROR msg=error
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
-
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()
 
@@ -97,8 +95,6 @@ level=ERROR msg=error
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
-
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()
 
@@ -178,7 +174,6 @@ func TestIsSamplingHandler(t *testing.T) {
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()
 
diff --git a/grpc/internal/recovery_test.go b/grpc/internal/recovery_test.go
index a6f0a05..649f0ea 100644
--- a/grpc/internal/recovery_test.go
+++ b/grpc/internal/recovery_test.go
@@ -45,8 +45,6 @@ func TestRecoveryUnaryInterceptor(t *testing.T) {
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
-
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()
 
@@ -95,15 +93,13 @@ func TestRecoveryStreamInterceptor(t *testing.T) {
 			handler: func(any, grpc.ServerStream) error {
 				panic("panic from handler")
 			},
-			log: `level=ERROR source=/recovery_test.go:96 msg="Panic Recovered" error="panic from handler"
+			log: `level=ERROR source=/recovery_test.go:94 msg="Panic Recovered" error="panic from handler"
 `,
 			err: "rpc error: code = Internal desc = ",
 		},
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
-
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()
 
diff --git a/grpc/server.go b/grpc/server.go
index d59e58b..f81a628 100644
--- a/grpc/server.go
+++ b/grpc/server.go
@@ -106,7 +106,6 @@ func Run(server *grpc.Server, opts ...Option) func(context.Context) error { //no
 		var waitGroup sync.WaitGroup
 		waitGroup.Add(len(option.addresses))
 		for _, addr := range option.addresses {
-			addr := addr
 			go func() {
 				defer waitGroup.Done()
 
diff --git a/grpc/server_test.go b/grpc/server_test.go
index a3cd0f9..f5fcfad 100644
--- a/grpc/server_test.go
+++ b/grpc/server_test.go
@@ -103,8 +103,6 @@ func TestRun(t *testing.T) {
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
-
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()
 
diff --git a/http/internal/buffer_test.go b/http/internal/buffer_test.go
index b60fbdb..70f7739 100644
--- a/http/internal/buffer_test.go
+++ b/http/internal/buffer_test.go
@@ -47,8 +47,6 @@ level=ERROR msg=error
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
-
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()
 
@@ -127,7 +125,6 @@ func TestIsSamplingHandler(t *testing.T) {
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()
 
diff --git a/http/internal/recovery_test.go b/http/internal/recovery_test.go
index 238d7b2..4587c4e 100644
--- a/http/internal/recovery_test.go
+++ b/http/internal/recovery_test.go
@@ -40,8 +40,6 @@ func TestRecoveryInterceptor(t *testing.T) {
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
-
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()
 
diff --git a/http/server.go b/http/server.go
index 2ed1767..533ba93 100644
--- a/http/server.go
+++ b/http/server.go
@@ -100,7 +100,6 @@ func Run(server *http.Server, opts ...Option) func(context.Context) error { //no
 			}
 		}
 		for _, addr := range option.addresses {
-			addr := addr
 			go func() {
 				defer waitGroup.Done()
 
diff --git a/otlp/go.mod b/otlp/go.mod
index 7ca2e25..dc40818 100644
--- a/otlp/go.mod
+++ b/otlp/go.mod
@@ -1,6 +1,6 @@
 module github.com/nil-go/nilgo/otlp
 
-go 1.21
+go 1.22
 
 require (
 	github.com/stretchr/testify v1.9.0
diff --git a/runner.go b/runner.go
index 5138f81..0bb06e7 100644
--- a/runner.go
+++ b/runner.go
@@ -59,7 +59,6 @@ func (r Runner) Run(ctx context.Context, runs ...func(context.Context) error) er
 		var waitGroup sync.WaitGroup
 		waitGroup.Add(len(r.preRuns))
 		for _, run := range r.preRuns {
-			run := run
 			preRuns = append(preRuns,
 				func(ctx context.Context) error {
 					waitGroup.Done()
@@ -131,7 +130,6 @@ func parallel(ctx context.Context, runs ...func(context.Context) error) error {
 	var waitGroup sync.WaitGroup
 	waitGroup.Add(len(runs))
 	for _, run := range runs {
-		run := run
 		go func() {
 			defer waitGroup.Done()
 
diff --git a/runner_test.go b/runner_test.go
index baf29ee..f01e6ef 100644
--- a/runner_test.go
+++ b/runner_test.go
@@ -88,8 +88,6 @@ func TestRunner_Run(t *testing.T) {
 	}
 
 	for _, testcase := range testcases {
-		testcase := testcase
-
 		var ran bool
 		t.Run(testcase.description, func(t *testing.T) {
 			t.Parallel()