diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 7b09b87..15f0073 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -28,7 +28,7 @@ jobs:
   query-extractor-yaml:
     strategy:
       matrix:
-        go-version: [1.19.x, 1.20.x]
+        go-version: [1.20.x, 1.21.x]
     runs-on: ubuntu-latest
     defaults:
       run:
@@ -48,11 +48,35 @@ jobs:
         name: query-extractor-yaml-coverage-report
         path: ./extractor/yaml/coverage.out
 
+  query-extractor-protobuf:
+    strategy:
+      matrix:
+        go-version: [1.20.x, 1.21.x]
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./extractor/protobuf
+    steps:
+    - name: Install Go
+      uses: actions/setup-go@v5.0.0
+      with:
+        go-version: ${{ matrix.go-version }}
+    - name: Checkout code
+      uses: actions/checkout@v4
+    - name: Test
+      run: go test -race ./... -coverpkg=./... -coverprofile=coverage.out -covermode=atomic
+    - uses: actions/upload-artifact@v4
+      if: startsWith(matrix.go-version, '1.20')
+      with:
+        name: query-extractor-protobuf-coverage-report
+        path: ./extractor/protobuf/coverage.out
+
   collect-metrics:
     name: collect metrics
     needs:
       - query
       - query-extractor-yaml
+      - query-extractor-protobuf
     runs-on: ubuntu-latest
     steps:
     - name: Checkout code
@@ -65,4 +89,8 @@ jobs:
       with:
         name: query-extractor-yaml-coverage-report
         path: ./extractor/yaml/coverage.out
+    - uses: actions/download-artifact@v4
+      with:
+        name: query-extractor-protobuf-coverage-report
+        path: ./extractor/protobuf/coverage.out
     - uses: k1LoW/octocov-action@v1
diff --git a/extractor/protobuf/go.mod b/extractor/protobuf/go.mod
index 9d5f7fa..3c57fdb 100644
--- a/extractor/protobuf/go.mod
+++ b/extractor/protobuf/go.mod
@@ -1,15 +1,10 @@
 module github.com/zoncoen/query-go/extractor/protobuf
 
-go 1.21.6
+go 1.20
 
 require (
 	github.com/zoncoen/query-go v1.3.0
-	github.com/zoncoen/query-go/extractor/protobuf/testdata/gen v0.0.0-00010101000000-000000000000
+	google.golang.org/protobuf v1.32.0
 )
 
-replace github.com/zoncoen/query-go/extractor/protobuf/testdata/gen => ./testdata/gen/
-
-require (
-	github.com/pkg/errors v0.9.1 // indirect
-	google.golang.org/protobuf v1.32.0 // indirect
-)
+require github.com/pkg/errors v0.9.1 // indirect
diff --git a/extractor/protobuf/testdata/gen/go.mod b/extractor/protobuf/testdata/gen/go.mod
deleted file mode 100644
index f03d51c..0000000
--- a/extractor/protobuf/testdata/gen/go.mod
+++ /dev/null
@@ -1,5 +0,0 @@
-module github.com/zoncoen/query-go/extractor/protobuf/testdata/gen
-
-go 1.21.6
-
-require google.golang.org/protobuf v1.32.0
diff --git a/extractor/protobuf/testdata/gen/go.sum b/extractor/protobuf/testdata/gen/go.sum
deleted file mode 100644
index 5361bc7..0000000
--- a/extractor/protobuf/testdata/gen/go.sum
+++ /dev/null
@@ -1,6 +0,0 @@
-github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
-github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-google.golang.org/protobuf v1.32.0 h1:pPC6BG5ex8PDFnkbrGU3EixyhKcQ2aDuBS36lqK/C7I=
-google.golang.org/protobuf v1.32.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=