diff --git a/src/lib/index.js b/src/lib/index.js
index e1ec4af..6314766 100644
--- a/src/lib/index.js
+++ b/src/lib/index.js
@@ -10,6 +10,14 @@ import runs from './runs.js'
 // sleep function
 const sleep = ms => new Promise(resolve => setTimeout(resolve, ms))
 
+// getting branch on pull_request event is different from push
+const getBranch = (payload) => {
+  if (payload.pull_request) {
+    return payload.pull_request.head.ref
+  }
+  return payload.ref.replace('refs/heads/', '')
+}
+
 export default async function ({ token, delay, timeout }) {
   let timer = 0
 
@@ -17,7 +25,7 @@ export default async function ({ token, delay, timeout }) {
   const octokit = github.getOctokit(token)
 
   // extract runId
-  const { runId: run_id } = github.context
+  const { payload, runId: run_id } = github.context
 
   // get workflow id and created date from run id
   const { data: { workflow_id, run_started_at } } = await octokit.request('GET /repos/{owner}/{repo}/actions/runs/{run_id}', {
@@ -30,8 +38,13 @@ export default async function ({ token, delay, timeout }) {
 
   core.info(`searching for workflow runs before ${before}`)
 
+  // branch to which to scope workflow runs
+  const branch = getBranch(payload)
+
+  core.info(`searching for workflow runs for branch ${branch}`)
+
   // get previous runs
-  let waiting_for = await runs({ octokit, run_id, workflow_id, before })
+  let waiting_for = await runs({ octokit, workflow_id, run_id, branch, before })
 
   if (waiting_for.length === 0) {
     core.info('no active run of this workflow found')
diff --git a/src/lib/runs.js b/src/lib/runs.js
index 6afc84a..b508421 100644
--- a/src/lib/runs.js
+++ b/src/lib/runs.js
@@ -7,11 +7,12 @@ import { inspect } from 'util'
 import core from '@actions/core'
 import github from '@actions/github'
 
-export default async function ({ octokit, workflow_id, run_id, before }) {
+export default async function ({ octokit, workflow_id, run_id, branch, before }) {
   // get current run of this workflow
   const { data: { workflow_runs } } = await octokit.request('GET /repos/{owner}/{repo}/actions/workflows/{workflow_id}/runs', {
     ...github.context.repo,
-    workflow_id
+    workflow_id,
+    branch
   })
 
   // find any instances of the same workflow