diff --git a/.github/workflows/example-basic.yml b/.github/workflows/example-basic.yml
index 63c96dc6..f19f3704 100644
--- a/.github/workflows/example-basic.yml
+++ b/.github/workflows/example-basic.yml
@@ -7,15 +7,9 @@ on:
 jobs:
   basic-example:
     runs-on: ubuntu-latest
-    env:
-      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Checkout
         uses: actions/checkout@v2
-        with:
-          fetch-depth: 0
-      - name: ls
-        run: npm ci
       - name: Renovate
         uses: ./
         with:
diff --git a/action.yml b/action.yml
index 2606747c..98a711bf 100644
--- a/action.yml
+++ b/action.yml
@@ -8,6 +8,4 @@ inputs:
     default: 'src/config.js'
 runs:
   using: 'docker'
-  image: 'src/dockerfile'
-  args:
-    - ${{ inputs.configurationFile }}
+  image: 'src/Dockerfile'
diff --git a/src/Dockerfile b/src/Dockerfile
new file mode 100644
index 00000000..3b19afa5
--- /dev/null
+++ b/src/Dockerfile
@@ -0,0 +1,5 @@
+FROM renovate/renovate:19.175.0
+
+COPY src/entrypoint.sh /usr/entrypoint.sh
+
+ENTRYPOINT ["/usr/entrypoint.sh"]
diff --git a/src/dockerfile b/src/dockerfile
deleted file mode 100644
index 4168d76a..00000000
--- a/src/dockerfile
+++ /dev/null
@@ -1,5 +0,0 @@
-FROM renovate/renovate:19.175.0
-
-COPY entrypoint.sh /entrypoint.sh
-
-ENTRYPOINT ["/entrypoint.sh"]
diff --git a/src/entrypoint.sh b/src/entrypoint.sh
index e70def06..74e5f2b8 100755
--- a/src/entrypoint.sh
+++ b/src/entrypoint.sh
@@ -2,9 +2,20 @@
 #
 # Entrypoint for Docker.
 
-configurationFile="${1}"
+readonly CONFIGURATION_FILE="${1}"
+readonly CONFIGURATION_PATH="${GITHUB_WORKSPACE}/${CONFIGURATION_FILE}"
 
-cp "${GITHUB_WORKSPACE}/${configurationFile}" '/usr/src/app/config.js'
+if [[ ! -f "${CONFIGURATION_PATH}" ]]; then
+  echo "ERROR: Couldn't find file ${CONFIGURATION_PATH}" 1>&2
+  exit 1
+fi
+
+cp "${CONFIGURATION_PATH}" '/usr/src/app/config.js'
 
 # Run Renovate.
+#
+# This mimics the original entrypoint of the renovate/renovate Docker container.
+# See the following link for this entrypoint in the renovate/renovate Docker
+# container.
+# https://github.com/renovatebot/renovate/blob/19.175.3/Dockerfile#L220
 node /usr/src/app/dist/renovate.js