diff --git a/.github/workflows/backport.yml b/.github/workflows/backport.yml
index 04ccdbd..c2db972 100644
--- a/.github/workflows/backport.yml
+++ b/.github/workflows/backport.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
 
     # Only run when pull request is merged
-    # or when a comment containing `/backport` is created
+    # or when a comment starting with `/backport` is created
     if: >
       (
         github.event_name == 'pull_request' &&
@@ -21,9 +21,9 @@ jobs:
       ) || (
         github.event_name == 'issue_comment' &&
         github.event.issue.pull_request &&
-        contains(github.event.comment.body, '/backport')
+        startsWith(github.event.comment.body, '/backport')
       )
     steps:
       - uses: actions/checkout@v4
       - name: Create backport pull requests
-        uses: korthout/backport-action@v2
\ No newline at end of file
+        uses: korthout/backport-action@v2
diff --git a/README.md b/README.md
index 65891be..bbb4b93 100644
--- a/README.md
+++ b/README.md
@@ -79,7 +79,7 @@ jobs:
     runs-on: ubuntu-latest
 
     # Only run when pull request is merged
-    # or when a comment containing `/backport` is created by someone other than the
+    # or when a comment starting with `/backport` is created by someone other than the
     # https://github.com/backport-action bot user (user id: 97796249). Note that if you use your
     # own PAT as `github_token`, that you should replace this id with yours.
     if: >
@@ -90,7 +90,7 @@ jobs:
         github.event_name == 'issue_comment' &&
         github.event.issue.pull_request &&
         github.event.comment.user.id != 97796249 &&
-        contains(github.event.comment.body, '/backport')
+        startsWith(github.event.comment.body, '/backport')
       )
     steps:
       - uses: actions/checkout@v4