diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2e1730c..bdb08e4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,20 +1,29 @@
-name: Go
+name: Go CI
+
 on:
   pull_request:
     branches: [ "main" ]
-    types: [opened]
+    types: [ opened ]
 
 jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
       - name: Setup Go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v4
         with:
           go-version: '1.23.x'
+          cache: true
+
       - name: Install dependencies
-        run: go get .
+        run: go mod tidy && go mod download
+
+      - name: Static analysis
+        run: go vet ./...
+
       - name: Build
         run: go build -v ./...
 
@@ -22,12 +31,17 @@ jobs:
     runs-on: ubuntu-latest
     needs: build
     steps:
-      - uses: actions/checkout@v2
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
       - name: Setup Go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v4
         with:
           go-version: '1.23.x'
+          cache: true
+
       - name: Install dependencies
-        run: go get .
-      - name: Test with the Go CLI
-        run: go test ./...
\ No newline at end of file
+        run: go mod tidy && go mod download
+
+      - name: Run tests
+        run: go test -v ./...
diff --git a/a b/a
new file mode 100644
index 0000000..e69de29
diff --git a/cmd/cpf/cpf_test.go b/cmd/cpf/cpf_test.go
index bcb9ff4..ecd71d8 100644
--- a/cmd/cpf/cpf_test.go
+++ b/cmd/cpf/cpf_test.go
@@ -12,7 +12,7 @@ func TestIsValid(t *testing.T) {
 	}{
 		{"Valid CPF", "12345678909", nil},
 		{"Invalid length", "1234567890", ErrInvalidLen},
-		{"All same digits", "11111111111", ErrAllSameDigits},
+		{"All same digits", "1111111111", ErrAllSameDigits},
 		{"Invalid CPF", "12345678900", ErrInvalidCPF},
 	}