diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 8f78b8d..004290c 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -4,6 +4,14 @@ on:
   workflow_dispatch:
 
 jobs:
+    downstream-wait:
+        runs-on: ubuntu-latest
+        steps:
+            - name: Checkout code
+              uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+            - name: Test downstream wait
+              run: bash downstream/wait.test.bash
+
     shopware-version-fallback:
         runs-on: ubuntu-latest
         steps:
@@ -113,4 +121,4 @@ jobs:
                 if [[ ! "$NEXT_MINOR" =~ ^v?[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
                     echo "next-minor looks wrong: '${NEXT_MINOR}'"
                     exit 1
-                fi
\ No newline at end of file
+                fi
diff --git a/downstream/README.md b/downstream/README.md
index 9366d2d..989f3f1 100644
--- a/downstream/README.md
+++ b/downstream/README.md
@@ -22,6 +22,7 @@ Trigger a downstream workflow in another repository and wait for it to finish.
 | `env` | Environment variables to pass to downstream workflow | No | - |
 | `identity` | Identity for octo-sts | No | `upstream` |
 | `token` | Token to authenticate (if not provided, octo-sts is used) | No | - |
+| `upstream-token` | Token used to cancel the upstream workflow run when the downstream run was cancelled | No | - |
 | `timeout` | Timeout for the downstream workflow | No | `30m` |
 | `poll_interval` | Poll interval for checking status | No | `2m` |
 
diff --git a/downstream/action.yml b/downstream/action.yml
index 6a9fb77..0a8a584 100644
--- a/downstream/action.yml
+++ b/downstream/action.yml
@@ -42,6 +42,10 @@ inputs:
     description: Token used to authenticate with the downstream repo. If not provided octo-sts is used
     required: false
     default: ""
+  upstream-token:
+    description: Token used to cancel the upstream workflow run when the downstream run was cancelled
+    required: false
+    default: ""
   timeout:
     description: Timeout for the downstream
     required: false
@@ -116,4 +120,7 @@ runs:
       env:
         GH_TOKEN: ${{ inputs.token || steps.sts.outputs.token }}
         REPO: ${{ inputs.repo }}
+        UPSTREAM_TOKEN: ${{ inputs.upstream-token }}
+        UPSTREAM_REPOSITORY: ${{ github.repository }}
+        UPSTREAM_RUN_ID: ${{ github.run_id }}
       run: timeout "${{ inputs.timeout }}" ${GITHUB_ACTION_PATH}/wait.bash "$REPO" "${{ inputs.poll_interval }}" "${{ steps.trigger.outputs.run_url }}"
diff --git a/downstream/wait.bash b/downstream/wait.bash
index 5573921..6bafcd3 100755
--- a/downstream/wait.bash
+++ b/downstream/wait.bash
@@ -2,12 +2,19 @@
 REPO=${1}
 POLL_INTERVAL=${2}
 DOWNSTREAM_RUN_URL=${3}
+CANCEL_REQUESTED=0
 
 DOWNSTREAM_RUN_ID=$(basename "$DOWNSTREAM_RUN_URL")
 
 trap on_sigterm SIGTERM
 
 on_sigterm() {
+    if [[ "${CANCEL_REQUESTED}" == "1" ]]; then
+        # GitHub sent SIGTERM after accepting our cancellation request.
+        echo "Upstream workflow cancellation is taking over."
+        exit 130
+    fi
+
     echo "Timeout reached"
     fail
 }
@@ -17,6 +24,27 @@ fail() {
     exit 1
 }
 
+cancel_upstream() {
+    if [[ -z "${UPSTREAM_TOKEN:-}" || -z "${UPSTREAM_REPOSITORY:-}" || -z "${UPSTREAM_RUN_ID:-}" ]]; then
+        return 1
+    fi
+
+    echo "Cancelling upstream workflow run ${UPSTREAM_RUN_ID} in ${UPSTREAM_REPOSITORY}."
+
+    if ! GH_TOKEN="${UPSTREAM_TOKEN}" gh run cancel "${UPSTREAM_RUN_ID}" --repo "${UPSTREAM_REPOSITORY}"; then
+        echo "Could not cancel upstream workflow run."
+        return 1
+    fi
+
+    CANCEL_REQUESTED=1
+
+    # gh run cancel only requests cancellation. Keep this step alive so GitHub
+    # can mark the upstream run as cancelled instead of racing our own failure.
+    while true; do
+        sleep 60
+    done
+}
+
 echo "Downstream workflow: ${DOWNSTREAM_RUN_URL}"
 
 ATTEMPT=1
@@ -36,9 +64,15 @@ while true; do
     sleep 60
 done
 
+if [[ "${STATUS}" == "cancelled" ]]; then
+    echo "Downstream workflow was cancelled."
+    cancel_upstream
+    fail
+fi
+
 if [[ "${STATUS}" != "success" ]]; then
-    echo "Downstream workflow failed."
+    echo "Downstream workflow concluded with '${STATUS}'."
     fail
 fi
 
-echo "Downstream workflow succeeded!"
\ No newline at end of file
+echo "Downstream workflow succeeded!"
diff --git a/downstream/wait.test.bash b/downstream/wait.test.bash
new file mode 100644
index 0000000..834d51a
--- /dev/null
+++ b/downstream/wait.test.bash
@@ -0,0 +1,63 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)
+TMP_DIR=$(mktemp -d)
+
+trap 'rm -rf "${TMP_DIR}"' EXIT
+
+cat > "${TMP_DIR}/gh" <<'EOF'
+#!/usr/bin/env bash
+if [[ "${1} ${2}" == "run view" ]]; then
+    printf '{"status":"completed","conclusion":"%s"}\n' "${GH_CONCLUSION}"
+    exit 0
+fi
+
+if [[ "${1} ${2}" == "run cancel" ]]; then
+    echo "cancel called"
+    exit "${GH_CANCEL_EXIT:-0}"
+fi
+
+exit 1
+EOF
+chmod +x "${TMP_DIR}/gh"
+
+run_case() {
+    local conclusion=${1}
+    local expected_code=${2}
+    local expected_message=${3}
+    local output
+    local code
+
+    set +e
+    output=$(PATH="${TMP_DIR}:${PATH}" GH_CONCLUSION="${conclusion}" bash "${SCRIPT_DIR}/wait.bash" shopware/example 1 https://github.com/shopware/example/actions/runs/1 2>&1)
+    code=$?
+    set -e
+
+    if [[ "${code}" -ne "${expected_code}" ]]; then
+        echo "Expected exit code ${expected_code} for ${conclusion}, got ${code}"
+        echo "${output}"
+        exit 1
+    fi
+
+    if [[ "${output}" != *"${expected_message}"* ]]; then
+        echo "Expected output for ${conclusion} to contain: ${expected_message}"
+        echo "${output}"
+        exit 1
+    fi
+}
+
+run_case success 0 "Downstream workflow succeeded!"
+run_case failure 1 "Downstream workflow concluded with 'failure'."
+run_case cancelled 1 "Downstream workflow was cancelled."
+
+set +e
+output=$(PATH="${TMP_DIR}:${PATH}" GH_CONCLUSION="cancelled" GH_CANCEL_EXIT=1 UPSTREAM_TOKEN=token UPSTREAM_REPOSITORY=shopware/shopware UPSTREAM_RUN_ID=1 bash "${SCRIPT_DIR}/wait.bash" shopware/example 1 https://github.com/shopware/example/actions/runs/1 2>&1)
+code=$?
+set -e
+
+if [[ "${code}" -ne 1 || "${output}" != *"Could not cancel upstream workflow run."* ]]; then
+    echo "Expected failed upstream cancellation to fall back to a failed downstream wait"
+    echo "${output}"
+    exit 1
+fi