diff --git a/.github/workflows/checks.yaml b/.github/workflows/checks.yaml
index 04c37ec..42cdf00 100644
--- a/.github/workflows/checks.yaml
+++ b/.github/workflows/checks.yaml
@@ -20,10 +20,10 @@ jobs:
         with:
           go-version: '1.24'
       - name: golangci-lint
-        # NOTE: https://github.com/golangci/golangci-lint-action/releases/tag/v6.5.2
-        uses: golangci/golangci-lint-action@55c2c1448f86e01eaae002a5a3a9624417608d84
+        # NOTE: https://github.com/golangci/golangci-lint-action/releases/tag/v8.0.0
+        uses: golangci/golangci-lint-action@4afd733a84b1f43292c63897423277bb7f4313a9
         with:
-          version: v1.64.5
+          version: v2.5.0
 
   static-check:
     name: Staticcheck
diff --git a/.golangci.yaml b/.golangci.yaml
index a5e537e..0cb9c98 100644
--- a/.golangci.yaml
+++ b/.golangci.yaml
@@ -1,4 +1,7 @@
+version: "2"
+
 linters:
+  default: none
   enable:
     - bodyclose
     - copyloopvar
@@ -7,28 +10,12 @@ linters:
     - gocritic
     - gocyclo
     - gosec
-    - gosimple
     - govet
     - ineffassign
     - misspell
     - nakedret
     - prealloc
-    # - revive
     - staticcheck
-    - stylecheck
-    - typecheck
     - unconvert
     - unparam
     - unused
-  fast: false
-  disable-all: true
-
-issues:
-  exclude-dirs:
-    - docs
-    - vendor
-  exclude-rules:
-    - path: _test\.go
-      linters:
-        - gosec
-        - dupl
diff --git a/internal/app/app_test.go b/internal/app/app_test.go
index 3914961..e0ec9a2 100644
--- a/internal/app/app_test.go
+++ b/internal/app/app_test.go
@@ -33,8 +33,14 @@ func Test_Run(t *testing.T) {
 				t.Setenv("OPENAI_API_KEY", "test-api-key")
 				tmpDir := t.TempDir()
 				originalWd, _ := os.Getwd()
-				os.Chdir(tmpDir)
-				return func() { os.Chdir(originalWd) }
+				if err := os.Chdir(tmpDir); err != nil {
+					t.Fatalf("failed to change directory: %v", err)
+				}
+				return func() {
+					if err := os.Chdir(originalWd); err != nil {
+						t.Errorf("failed to restore directory: %v", err)
+					}
+				}
 			},
 			expectedExitCode: 1,
 		},
@@ -47,13 +53,19 @@ func Test_Run(t *testing.T) {
 				originalArgs := os.Args
 
 				configPath := filepath.Join(tmpDir, "cmt.yaml")
-				os.WriteFile(configPath, []byte("gpt:\n  model: gpt-4\n"), 0644)
+				if err := os.WriteFile(configPath, []byte("gpt:\n  model: gpt-4\n"), 0600); err != nil {
+					t.Fatalf("failed to write config: %v", err)
+				}
 
-				os.Chdir(tmpDir)
+				if err := os.Chdir(tmpDir); err != nil {
+					t.Fatalf("failed to change directory: %v", err)
+				}
 				os.Args = []string{"cmt", "help"}
 
 				return func() {
-					os.Chdir(originalWd)
+					if err := os.Chdir(originalWd); err != nil {
+						t.Errorf("failed to restore directory: %v", err)
+					}
 					os.Args = originalArgs
 				}
 			},
diff --git a/internal/app/git/git_test.go b/internal/app/git/git_test.go
index 56717ca..8818fbf 100644
--- a/internal/app/git/git_test.go
+++ b/internal/app/git/git_test.go
@@ -147,6 +147,7 @@ func Test_Diff(t *testing.T) {
 	}
 }
 
+//nolint:dupl
 func Test_Log(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
@@ -234,6 +235,7 @@ func Test_Log(t *testing.T) {
 	}
 }
 
+//nolint:dupl
 func Test_Status(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index fb30341..b89ae6c 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -14,7 +14,7 @@ func writeTempConfig(t *testing.T, contents string) string {
 	t.Helper()
 	tmpDir := t.TempDir()
 	configPath := filepath.Join(tmpDir, "cmt.yaml")
-	err := os.WriteFile(configPath, []byte(contents), 0644)
+	err := os.WriteFile(configPath, []byte(contents), 0600)
 	if err != nil {
 		t.Fatalf("failed to write temp config: %v", err)
 	}
@@ -53,8 +53,14 @@ func Test_Load_WithInvalidConfig(t *testing.T) {
 
 	tmpDir := writeTempConfig(t, configContent)
 	originalWd, _ := os.Getwd()
-	os.Chdir(tmpDir)
-	defer os.Chdir(originalWd)
+	if err := os.Chdir(tmpDir); err != nil {
+		t.Fatalf("failed to change directory: %v", err)
+	}
+	defer func() {
+		if err := os.Chdir(originalWd); err != nil {
+			t.Errorf("failed to restore directory: %v", err)
+		}
+	}()
 
 	cfg, err := Load()
 
@@ -70,8 +76,14 @@ func Test_Load_WithBadYAML(t *testing.T) {
 
 	tmpDir := writeTempConfig(t, configContent)
 	originalWd, _ := os.Getwd()
-	os.Chdir(tmpDir)
-	defer os.Chdir(originalWd)
+	if err := os.Chdir(tmpDir); err != nil {
+		t.Fatalf("failed to change directory: %v", err)
+	}
+	defer func() {
+		if err := os.Chdir(originalWd); err != nil {
+			t.Errorf("failed to restore directory: %v", err)
+		}
+	}()
 
 	cfg, err := Load()