diff --git a/src/commits.ts b/src/commits.ts
index 274f681..45f7341 100755
--- a/src/commits.ts
+++ b/src/commits.ts
@@ -8,7 +8,6 @@ export interface CommitInfo {
   message: string
   author: string
   date: moment.Moment
-  prNumber: number | undefined
 }
 
 export class Commits {
diff --git a/src/pullRequests.ts b/src/pullRequests.ts
index 6310228..f7e7ff5 100755
--- a/src/pullRequests.ts
+++ b/src/pullRequests.ts
@@ -9,6 +9,7 @@ export interface PullRequestInfo {
   title: string
   htmlURL: string
   mergedAt: moment.Moment
+  mergeCommitSha: string
   author: string
   repoName: string
   labels: string[]
@@ -38,6 +39,7 @@ export class PullRequests {
         title: pr.data.title,
         htmlURL: pr.data.html_url,
         mergedAt: moment(pr.data.merged_at),
+        mergeCommitSha: pr.data.merge_commit_sha,
         author: pr.data.user.login,
         repoName: pr.data.base.repo.full_name,
         labels: pr.data.labels.map(function (label) {
@@ -88,6 +90,7 @@ export class PullRequests {
           title: pr.title,
           htmlURL: pr.html_url,
           mergedAt: moment(pr.merged_at),
+          mergeCommitSha: pr.merge_commit_sha,
           author: pr.user.login,
           repoName: pr.base.repo.full_name,
           labels: pr.labels?.map(function (label) {
@@ -121,11 +124,13 @@ export class PullRequests {
     return sortPullRequests(mergedPRs, true)
   }
 
+  /**
+   * Filters out all commits which match the exclude pattern
+   */
   filterCommits(
     commits: CommitInfo[],
     excludeMergeBranches: string[]
   ): CommitInfo[] {
-    const prRegex = /Merge pull request #(\d+)/
     const filteredCommits = []
 
     for (const commit of commits) {
@@ -141,12 +146,6 @@ export class PullRequests {
           continue
         }
       }
-
-      const match = commit.summary.match(prRegex)
-      if (!match) {
-        continue
-      }
-      commit.prNumber = Number.parseInt(match[1], 10)
       filteredCommits.push(commit)
     }
 
diff --git a/src/releaseNotes.ts b/src/releaseNotes.ts
index 3f8e3d7..b00113d 100755
--- a/src/releaseNotes.ts
+++ b/src/releaseNotes.ts
@@ -107,42 +107,17 @@ export class ReleaseNotes {
     )
 
     core.info(
-      `ℹ️ Retrieved ${prCommits.length} PR merge commits for ${owner}/${repo}`
+      `ℹ️ Retrieved ${prCommits.length} release commits for ${owner}/${repo}`
     )
 
-    const filteredPullRequests = []
-    const pullRequestsByNumber: {[key: number]: PullRequestInfo} = {}
+    // create array of commits for this release
+    const releaseCommitHashes = prCommits.map(commmit => {
+      return commmit.sha
+    })
 
-    for (const pr of pullRequests) {
-      pullRequestsByNumber[pr.number] = pr
-    }
-
-    for (const commit of prCommits) {
-      if (!commit.prNumber) {
-        continue
-      }
-
-      const prRef = `${owner}/${repo}#${commit.prNumber}`
-
-      if (pullRequestsByNumber[commit.prNumber]) {
-        filteredPullRequests.push(pullRequestsByNumber[commit.prNumber])
-      } else if (fromDate.toISOString() === toDate.toISOString()) {
-        const pullRequest = await pullRequestsApi.getSingle(
-          owner,
-          repo,
-          commit.prNumber
-        )
-
-        if (pullRequest) {
-          filteredPullRequests.push(pullRequest)
-        } else {
-          core.warning(`⚠️ ${prRef} not found! Commit text: ${commit.summary}`)
-        }
-      } else {
-        core.info(`ℹ️ ${prRef} not in date range, excluding from changelog`)
-      }
-    }
-
-    return filteredPullRequests
+    // return only the pull requests associated with this release
+    return pullRequests.filter(pr => {
+      return releaseCommitHashes.includes(pr.mergeCommitSha)
+    })
   }
 }