diff --git a/.github/workflows/check.yaml b/.github/workflows/check.yaml
index 459de01..a0e71cd 100644
--- a/.github/workflows/check.yaml
+++ b/.github/workflows/check.yaml
@@ -8,6 +8,10 @@ name: Check
   schedule:
     - cron: 6 6 * * 6
 
+defaults:
+  run:
+    shell: bash
+
 permissions:
   checks: write
   contents: read
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 5980fa7..89a26cc 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -5,6 +5,10 @@ name: Release a new version
     tags:
       - v*.*.*
 
+defaults:
+  run:
+    shell: bash
+
 env:
   DOCKER_HUB_IMAGE: mm62/tmpbbs