diff --git a/.github/workflows/depup.yml b/.github/workflows/depup.yml
index af12193..d2f10a3 100644
--- a/.github/workflows/depup.yml
+++ b/.github/workflows/depup.yml
@@ -7,7 +7,7 @@ on:
       - '**'
 
 jobs:
-  depup:
+  reviewdog:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -30,3 +30,27 @@ jobs:
             This PR is auto generated by [depup workflow](https://github.com/${{ github.repository }}/actions?query=workflow%3Adepup).
           branch: depup/reviewdog
           base: master
+
+  redpen:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ./
+        id: depup
+        with:
+          file: testdata/testfile
+          version_name: REDPEN_VERSION
+          repo: redpen-cc/redpen
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          title: "chore(deps): update redpen to ${{ steps.depup.outputs.latest }}"
+          commit-message: "chore(deps): update redpen to ${{ steps.depup.outputs.latest }}"
+          body: |
+            Update redpen to [${{ steps.depup.outputs.latest }}](https://github.com/redpen-cc/redpen/releases/tag/redpen-${{ steps.depup.outputs.latest }})
+
+            This PR is auto generated by [depup workflow](https://github.com/${{ github.repository }}/actions?query=workflow%3Adepup).
+          branch: depup/redpen
+          base: master
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d3d514a..9d5a1f0 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -18,3 +18,17 @@ jobs:
 
       - name: Check diff
         run: git diff
+
+  needless_prefix:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ./
+        id: depup
+        with:
+          file: testdata/testfile
+          version_name: REDPEN_VERSION
+          repo: redpen-cc/redpen
+
+      - name: Check diff
+        run: git diff
diff --git a/entrypoint.sh b/entrypoint.sh
index d8b7314..7d3502f 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -30,8 +30,7 @@ list_releases() {
 LATEST_VERSION=$(\
   list_releases | \
   jq -r '.[] | .tag_name' | \
-  sed 's/^v//' | \
-  grep -P '\d+\.\d+\.\d+' | \
+  grep -oP '\d+\.\d+\.\d+$' | \
   sort --version-sort --reverse | \
   head -n1
 )
diff --git a/testdata/testfile b/testdata/testfile
index 41bc285..33f8ca0 100644
--- a/testdata/testfile
+++ b/testdata/testfile
@@ -10,3 +10,7 @@ yaml:
 
 The above version should be updated to the latest version with this action.
 
+
+Other test cases.
+
+REDPEN_VERSION=1.10.1