diff --git a/github-actions/release-prepare/.env.example b/github-actions/release-prepare/.env.example
new file mode 100644
index 0000000..c024a67
--- /dev/null
+++ b/github-actions/release-prepare/.env.example
@@ -0,0 +1,4 @@
+GITHUB_TOKEN=PASTE_YOUR_TOKEN
+GITHUB_REPOSITORY=exampleorg/exampleproject
+RELEASE_BRANCH=main
+GITHUB_REF_NAME=develop
diff --git a/github-actions/release-prepare/.gitignore b/github-actions/release-prepare/.gitignore
new file mode 100644
index 0000000..4c49bd7
--- /dev/null
+++ b/github-actions/release-prepare/.gitignore
@@ -0,0 +1 @@
+.env
diff --git a/github-actions/release-prepare/README.md b/github-actions/release-prepare/README.md
new file mode 100644
index 0000000..f2790ba
--- /dev/null
+++ b/github-actions/release-prepare/README.md
@@ -0,0 +1,19 @@
+# GitHub Action: release-prepare
+
+## Development
+
+This action encapsulates most of its complexity in a standalone Bash script that accepts environment variables, making it easy to test locally with the help of a `.env` file you can point at a test repository.
+
+1. Create `.env` from the template:
+
+    ```bash
+    cp .env.example .env
+    ```
+
+2. Paste a GitHub token and tailor repository/branches to your test target.
+
+3. Run bash script with `.env` applied to emulate GitHub Actions context:
+
+    ```bash
+    eval $(< .env) ./pull-request.sh
+    ```
diff --git a/github-actions/release-prepare/pull-request.sh b/github-actions/release-prepare/pull-request.sh
index d2e042d..d789c1f 100755
--- a/github-actions/release-prepare/pull-request.sh
+++ b/github-actions/release-prepare/pull-request.sh
@@ -29,18 +29,25 @@ EOF
 
 # create or update PR
 echo "Looking for existing PR..."
-pr_number=$(gh pr view "${GITHUB_REF_NAME}" --json number --jq '.number')
+pr_number=$(
+    gh pr view "${GITHUB_REF_NAME}" \
+        --json number,state \
+        --template '{{.number}}{{"\t"}}{{.state}}' \
+    | grep OPEN \
+    | awk '{print $1}'
+)
 
 if [ -n "${pr_number}" ]; then
     echo "Found existing PR #${pr_number}, looking for existing comment..."
     existing_comment_id=$(gh api "/repos/${GITHUB_REPOSITORY}/issues/${pr_number}/comments" --jq '.[] | select(.body | startswith("## Changelog\n\n")) | .id')
 else
     echo "Opening PR..."
-    pr_url=$(gh pr create \
-        --base "${RELEASE_BRANCH}" \
-        --head "${GITHUB_REF_NAME}" \
-        --title "${pr_title}" \
-        --body "${pr_body}"
+    pr_url=$(
+        gh pr create \
+            --base "${RELEASE_BRANCH}" \
+            --head "${GITHUB_REF_NAME}" \
+            --title "${pr_title}" \
+            --body "${pr_body}"
     )
     pr_number="${pr_url##*/}"
     echo "Opened PR #${pr_number}"