diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1912d380..84a87dbf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -33,7 +33,7 @@ env:
   MANPAGE_DIR: "target/tmp/bottom/manpage/"
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event.ref }}
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: ${{ github.event_name == 'pull_request' || github.repository != 'ClementTsang/bottom' }}
 
 jobs:
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index 0613145b..fef57635 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -14,7 +14,7 @@ env:
   CARGO_INCREMENTAL: 0
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event.ref }}
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: ${{ github.event_name == 'pull_request' || github.repository != 'ClementTsang/bottom' }}
 
 jobs:
diff --git a/.github/workflows/test-docs.yml b/.github/workflows/test-docs.yml
index 8364e493..219d3cb2 100644
--- a/.github/workflows/test-docs.yml
+++ b/.github/workflows/test-docs.yml
@@ -6,7 +6,7 @@ on:
   pull_request:
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event.ref }}
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: ${{ github.event_name == 'pull_request' || github.repository != 'ClementTsang/bottom' }}
 
 jobs: