diff --git a/.github/workflows/depup.yml b/.github/workflows/depup.yml
index d2f10a3..7a48f2f 100644
--- a/.github/workflows/depup.yml
+++ b/.github/workflows/depup.yml
@@ -19,7 +19,7 @@ jobs:
           repo: reviewdog/reviewdog
 
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v2
+        uses: peter-evans/create-pull-request@v3
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           title: "chore(deps): update reviewdog to ${{ steps.depup.outputs.latest }}"
@@ -43,7 +43,7 @@ jobs:
           repo: redpen-cc/redpen
 
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v2
+        uses: peter-evans/create-pull-request@v3
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           title: "chore(deps): update redpen to ${{ steps.depup.outputs.latest }}"
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3474307
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+# Files to ignore
+
+# Folders to ignore
+.vscode/
+*.code-workspace
\ No newline at end of file
diff --git a/Dockerfile b/Dockerfile
index 0d29f94..2b184d1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 FROM alpine:3.10
 
-RUN apk --no-cache add git jq curl grep coreutils
+RUN apk --no-cache add git jq curl grep coreutils perl
 
 COPY entrypoint.sh /entrypoint.sh
 
diff --git a/README.md b/README.md
index 2cb1573..bf680d1 100644
--- a/README.md
+++ b/README.md
@@ -77,7 +77,7 @@ jobs:
           repo: reviewdog/reviewdog
 
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v2
+        uses: peter-evans/create-pull-request@v3
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           title: "chore(deps): update reviewdog to ${{ steps.depup.outputs.latest }}"
diff --git a/entrypoint.sh b/entrypoint.sh
index 40ecd25..4b47069 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -5,12 +5,13 @@ if [ -n "${GITHUB_WORKSPACE}" ]; then
   cd "${GITHUB_WORKSPACE}" || exit
 fi
 
-FILE="${INPUT_FILE:-Dockerfile}"
+FILE="${INPUT_FILE:-testdata/testfile}"
 REPO="${INPUT_REPO:-reviewdog/reviewdog}"
 VERSION_NAME="${INPUT_VERSION_NAME:-REVIEWDOG_VERSION}"
 
 # Get current version.
-CURRENT_VERSION=$(grep -oP "${VERSION_NAME}\s*(=|:?)\s*(\'|\")?v?\K\d+\.\d+(\.\d+)?" "${FILE}" | head -n1)
+# NOTE: Go to https://regex101.com/r/t1JcmL/13 To see the current regex in action.
+CURRENT_VERSION=$(grep -oP "${VERSION_NAME}(?:\s*=\s*|:?\s*)[\"|\']?v?\K\d+\.\d+(\.\d+)?(-[^\'\"\s]*)?" "${FILE}" | head -n1)
 if [ -z "${CURRENT_VERSION}" ]; then
   echo "cannot parse ${VERSION_NAME}"
   exit 1
@@ -26,13 +27,13 @@ list_releases() {
     curl -s "https://api.github.com/repos/${REPO}/releases"
   fi
 }
-LATEST_VERSION=$(\
+LATEST_VERSION="$(\
   list_releases | \
   jq -r '.[] | .tag_name' | \
-  grep -oP '\d+\.\d+(\.\d+)?$' | \
+  grep -oP '\d+\.\d+(\.\d+)?(-[^'\''\"\s]*)?$' | \
   sort --version-sort --reverse | \
-  head -n1
-)
+  head -n1 \
+)"
 if [ -z "${LATEST_VERSION}" ]; then
   echo "cannot get latest ${REPO} version"
   exit 1
@@ -45,8 +46,9 @@ if [ "${CURRENT_VERSION}" = "${LATEST_VERSION}" ]; then
 fi
 
 echo "Updating ${VERSION_NAME} to ${LATEST_VERSION} in ${FILE}"
-sed -i "s/\(${VERSION_NAME}\s*\(=\|:\?\)\s*\('\|\"\)\?v\?\)\([0-9]\+\.[0-9]\+\(\.\?[0-9]\+\)\?\)/\1${LATEST_VERSION}/" "${FILE}"
+perl -i -pe "s/${VERSION_NAME}(?:\s*=\s*|:?\s*)[\"|\']?v?\K\d+\.\d+(\.\d+)?(-[^\'\"\s]*)?/${LATEST_VERSION}/g" "${FILE}"
 
 echo "Updated. Commit and create Pull-Request as you need."
 echo "::set-output name=current::${CURRENT_VERSION}"
 echo "::set-output name=latest::${LATEST_VERSION}"
+echo "::set-output name=repo::${REPO}"
diff --git a/testdata/testfile b/testdata/testfile
index 7abc19f..3d1c073 100644
--- a/testdata/testfile
+++ b/testdata/testfile
@@ -1,12 +1,32 @@
 This is test file.
 
 REVIEWDOG_VERSION=v0.1.0
+REVIEWDOG_VERSION = v0.1.0
 REVIEWDOG_VERSION=0.1.0
+REVIEWDOG_VERSION = 0.1.0
+REVIEWDOG_VERSION="v0.1.0"
+REVIEWDOG_VERSION='v0.1.0'
+REVIEWDOG_VERSION = "v0.1.0"
+REVIEWDOG_VERSION = 'v0.1.0'
+REVIEWDOG_VERSION="0.1.0"
+REVIEWDOG_VERSION='0.1.0'
+REVIEWDOG_VERSION = "0.1.0"
+REVIEWDOG_VERSION = '0.1.0'
+REVIEWDOG_VERSION="v0.1.0-nightly20201208+12faa31"
+REVIEWDOG_VERSION='v0.1.0-nightly20201208+12faa31'
+REVIEWDOG_VERSION = "v0.1.0-nightly20201208+12faa31"
+REVIEWDOG_VERSION = 'v0.1.0-nightly20201208+12faa31'
+REVIEWDOG_VERSION="0.1.0-nightly20201208+12faa31"
+REVIEWDOG_VERSION='0.1.0-nightly20201208+12faa31'
+REVIEWDOG_VERSION = "0.1.0-nightly20201208+12faa31"
+REVIEWDOG_VERSION = '0.1.0-nightly20201208+12faa31'
 ENV REVIEWDOG_VERSION=0.1.0
 ENV REVIEWDOG_VERSION 0.1.0
 ARG REVIEWDOG_VERSION=0.1.0
 yaml:
   REVIEWDOG_VERSION: 0.1.0
+  REVIEWDOG_VERSION: "0.1.0"
+  REVIEWDOG_VERSION: '0.1.0'
 
 The above version should be updated to the latest version with this action.