diff --git a/Dockerfile b/Dockerfile
index 9d86ea3..4794a33 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,10 +1,15 @@
 #######################################
 # image for dev build environment
 ######################################
-FROM golang:1.16.3-alpine as DEV
+FROM alpine:3.13 as dev
+
+ARG GH_CLI_VER=1.9.2
 
 # install packages
-RUN apk add --update --no-cache bash make git zsh curl tmux musl build-base openssh
+RUN apk add --update --no-cache bash make git zsh curl tmux musl
+
+RUN wget https://github.com/cli/cli/releases/download/v${GH_CLI_VER}/gh_${GH_CLI_VER}_linux_386.tar.gz -O ghcli.tar.gz
+RUN tar --strip-components=1 -xf ghcli.tar.gz
 
 # Make zsh your default shell for tmux
 RUN echo "set-option -g default-shell /bin/zsh" >> /root/.tmux.conf
@@ -12,27 +17,12 @@ RUN echo "set-option -g default-shell /bin/zsh" >> /root/.tmux.conf
 # install oh-my-zsh
 RUN sh -c "$(curl -fsSL https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)"
 
-# github-cli not stable yet
-#RUN git clone https://github.com/cli/cli.git gh-cli \
-#    && cd gh-cli \
-#    && make \
-#    && mv ./bin/gh /usr/local/bin/
-
-RUN apk add --update --no-cache groff util-linux
-RUN git clone \
-  --config transfer.fsckobjects=false \
-  --config receive.fsckobjects=false \
-  --config fetch.fsckobjects=false \
-  https://github.com/github/hub.git \
- && cd hub \
- && make install prefix=/usr/local
-
 WORKDIR /app
 
 #######################################
 # image for creating the documentation
 ######################################
-FROM node:16.0.0-alpine as DOCS
+FROM node:16.0.0-alpine as docs
 
 # install packages
 RUN apk add --update --no-cache bash make git zsh curl tmux
diff --git a/README.md b/README.md
index 5286d20..23a36f2 100644
--- a/README.md
+++ b/README.md
@@ -37,10 +37,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
       - name: actions-template-sync
-        uses: AndreasAugustin/actions-template-sync@v0.1.1-draft
+        uses: AndreasAugustin/actions-template-sync@v0.1.2-draft
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           source_repo_path: <owner/repo>
+          upstream_branch: <target_branch> # defaults to main
 ```
 
 You will receive a pull request within your repository if there are some changes available.
diff --git a/action.yml b/action.yml
index 31bf842..0c66973 100644
--- a/action.yml
+++ b/action.yml
@@ -11,9 +11,14 @@ inputs:
   source_repo_path:
     description: 'Repository path of the template'
     required: true
+  upstream_branch:
+    description: 'The target branch'
+    required: true
+    default: 'main'
 runs:
   using: 'docker'
   image: 'src/Dockerfile'
   env:
     GITHUB_TOKEN: ${{ inputs.github_token }}
     SOURCE_REPO_PATH: ${{ inputs.source_repo_path }}
+    UPSTREAM_BRANCH: ${{ inputs.upstream_branch }}
diff --git a/docker-compose.yml b/docker-compose.yml
index 88a3b7b..ce5b08e 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -4,7 +4,7 @@ services:
   dev:
     build:
       context: .
-      target: DEV
+      target: dev
     volumes:
       - .:/app/
       - ~/.gitconfig:/root/.gitconfig:ro
@@ -13,6 +13,6 @@ services:
   docs:
     build:
       context: .
-      target: DOCS
+      target: docs
     volumes:
       - .:/app/
diff --git a/src/Dockerfile b/src/Dockerfile
index b24c8db..4701600 100644
--- a/src/Dockerfile
+++ b/src/Dockerfile
@@ -1,4 +1,7 @@
-FROM golang:1.14-alpine
+FROM alpine:3.13
+
+ARG GH_CLI_VER=1.9.2
+
 # labels
 LABEL \
   "name"="GitHub template sync" \
@@ -7,22 +10,10 @@ LABEL \
   "maintainer"="Andreas Augustin <dev@andreas-augustin.org>"
 
 # install packages
-RUN apk add --update --no-cache bash make git zsh curl tmux musl build-base
-
-# github-cli not stable yet
-#RUN git clone https://github.com/cli/cli.git gh-cli \
-#    && cd gh-cli \
-#    && make \
-#    && mv ./bin/gh /usr/local/bin/
+RUN apk add --update --no-cache bash git curl musl
 
-RUN apk add --update --no-cache groff util-linux
-RUN git clone \
-  --config transfer.fsckobjects=false \
-  --config receive.fsckobjects=false \
-  --config fetch.fsckobjects=false \
-  https://github.com/github/hub.git \
- && cd hub \
- && make install prefix=/usr/local
+RUN wget https://github.com/cli/cli/releases/download/v${GH_CLI_VER}/gh_${GH_CLI_VER}_linux_386.tar.gz -O ghcli.tar.gz
+RUN tar --strip-components=1 -xf ghcli.tar.gz
 
 ADD *.sh /bin/
 RUN chmod +x /bin/entrypoint.sh \
diff --git a/src/sync_template.sh b/src/sync_template.sh
index 34cb434..eb9ca60 100755
--- a/src/sync_template.sh
+++ b/src/sync_template.sh
@@ -6,32 +6,52 @@ if [[ -z "${SOURCE_REPO}" ]]; then
   exit 1;
 fi
 
-# if ! [ -x "$(command -v gh)" ]; then
-#   echo "Error: github-cli gh is not installed. 'https://github.com/cli/cli'" >&2;
-#   exit 1;
-# fi
+if [[ -z "${UPSTREAM_BRANCH}" ]]; then
+  echo "Error: Missing env variable 'UPSTREAM_BRANCH'" >&2;
+  exit 1;
+fi
 
-if ! [ -x "$(command -v hub)" ]; then
-  echo "Error: hub is not installed. 'https://github.com/github/hub'" >&2;
+if ! [ -x "$(command -v gh)" ]; then
+  echo "Error: github-cli gh is not installed. 'https://github.com/cli/cli'" >&2;
   exit 1;
 fi
 
-NEW_BRANCH="chore/template_sync"
+TEMPLATE_VERSION_FILE_NAME=".templateversionrc"
+TEMPLATE_REMOTE_GIT_HASH=$(git ls-remote "${SOURCE_REPO}" HEAD | awk {'print $1}')
+NEW_TEMPLATE_GIT_HASH=$(git rev-parse --short "${TEMPLATE_REMOTE_GIT_HASH}")
+NEW_BRANCH="chore/template_sync_${NEW_TEMPLATE_GIT_HASH}"
 
 echo "start sync"
 echo "create new branch from default branch with name ${NEW_BRANCH}"
-git checkout -b ${NEW_BRANCH}
+git checkout -b "${NEW_BRANCH}"
 echo "pull changes from template"
 git pull "${SOURCE_REPO}" --allow-unrelated-histories --squash --strategy=recursive -X theirs
+
+echo "new Git HASH ${NEW_TEMPLATE_GIT_HASH}"
+if [ -r ${TEMPLATE_VERSION_FILE_NAME} ]
+then
+  CURRENT_TEMPLATE_GIT_HASH=$(cat ${TEMPLATE_VERSION_FILE_NAME})
+  echo "Current git hash ${CURRENT_TEMPLATE_GIT_HASH}"
+fi
+
+if [ "${NEW_TEMPLATE_GIT_HASH}" == "${CURRENT_TEMPLATE_GIT_HASH}" ]
+then
+  echo "repository is up to date"
+  exit 0
+fi
+
+echo "write new template version file"
+echo "${NEW_TEMPLATE_GIT_HASH}" > ${TEMPLATE_VERSION_FILE_NAME}
+echo "wrote new template version file with content $(cat ${TEMPLATE_VERSION_FILE_NAME})"
+
 git add .
 git commit -m "chore(template): merge template changes :up:"
+
 echo "push changes"
 git push --set-upstream origin "${NEW_BRANCH}"
 echo "create pull request"
-# Workaround for `hub` auth error https://github.com/github/hub/issues/2149#issuecomment-513214342
-export GITHUB_USER="$GITHUB_ACTOR"
-hub pull-request \
-  -b master \
-  -h $NEW_BRANCH \
-  --no-edit
-# gh pr create -B master -f -l chore
+
+gh pr create \
+  --title "upstream merge template repository" \
+  --body "Merge ${SOURCE_REPO_PATH} ${NEW_TEMPLATE_GIT_HASH}" \
+  -B "${UPSTREAM_BRANCH}"