diff --git a/entrypoint.sh b/entrypoint.sh
index 99dafff..f652ced 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -10,7 +10,7 @@ REPO="${INPUT_REPO:-reviewdog/reviewdog}"
 VERSION_NAME="${INPUT_VERSION_NAME:-REVIEWDOG_VERSION}"
 
 # Get current version.
-CURRENT_VERSION=$(grep -oP "${VERSION_NAME}(=|:?\s+)v?\K\d+\.\d+\.\d+" "${FILE}" | head -n1)
+CURRENT_VERSION=$(grep -oP "${VERSION_NAME}(=|:?\s+)v?\K\d+\.\d+(\.\d+)?" "${FILE}" | head -n1)
 if [ -z "${CURRENT_VERSION}" ]; then
   echo "cannot parse ${VERSION_NAME}"
   exit 1
@@ -29,7 +29,7 @@ list_releases() {
 LATEST_VERSION=$(\
   list_releases | \
   jq -r '.[] | .tag_name' | \
-  grep -oP '\d+\.\d+\.\d+$' | \
+  grep -oP '\d+\.\d+(\.\d+)?$' | \
   sort --version-sort --reverse | \
   head -n1
 )
@@ -45,7 +45,7 @@ if [ "${CURRENT_VERSION}" = "${LATEST_VERSION}" ]; then
 fi
 
 echo "Updating ${VERSION_NAME} to ${LATEST_VERSION} in ${FILE}"
-sed -i "s/\(${VERSION_NAME}\(=\|:\?\s\+\)v\?\)\([0-9]\+\.[0-9]\+\.\?[0-9]\+\)/\1${LATEST_VERSION}/" "${FILE}"
+sed -i "s/\(${VERSION_NAME}\(=\|:\?\s\+\)v\?\)\([0-9]\+\.[0-9]\+\(\.\?[0-9]\+\)\?\)/\1${LATEST_VERSION}/" "${FILE}"
 
 echo "Updated. Commit and create Pull-Request as you need."
 echo "::set-output name=current::${CURRENT_VERSION}"