diff --git a/.github/workflows/backport.yml b/.github/workflows/backport.yml
index d1caf26b..280fd19d 100644
--- a/.github/workflows/backport.yml
+++ b/.github/workflows/backport.yml
@@ -11,6 +11,10 @@ permissions:
   contents: read
   pull-requests: write
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   backport:
     runs-on: ubuntu-24.04
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 8cc40975..29b73d2b 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -11,6 +11,10 @@ on:
 permissions:
   contents: read
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   check:
     name: ${{ matrix.name }}
diff --git a/.github/workflows/conflicts.yml b/.github/workflows/conflicts.yml
index 77ec7046..59569257 100644
--- a/.github/workflows/conflicts.yml
+++ b/.github/workflows/conflicts.yml
@@ -7,6 +7,10 @@ on:
       - master
       - release-**
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   conflicts:
     runs-on: ubuntu-24.04
diff --git a/.github/workflows/doc.yml b/.github/workflows/doc.yml
index 3441d2f9..df1b9ab1 100644
--- a/.github/workflows/doc.yml
+++ b/.github/workflows/doc.yml
@@ -10,6 +10,10 @@ concurrency:
   cancel-in-progress: true
   group: pages
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   docs:
     runs-on: ubuntu-24.04
diff --git a/.github/workflows/labels.yml b/.github/workflows/labels.yml
index 4623aed5..8968169a 100644
--- a/.github/workflows/labels.yml
+++ b/.github/workflows/labels.yml
@@ -17,6 +17,10 @@ permissions:
   contents: read
   pull-requests: write
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   labels:
     name: label-pr
diff --git a/.github/workflows/request-reviewers.yml b/.github/workflows/request-reviewers.yml
index 4ab5e94a..c16656ca 100644
--- a/.github/workflows/request-reviewers.yml
+++ b/.github/workflows/request-reviewers.yml
@@ -7,6 +7,10 @@ on:
     paths:
       - 'modules/**'
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   request-reviewers:
     runs-on: ubuntu-24.04
diff --git a/.github/workflows/update-flake.yml b/.github/workflows/update-flake.yml
index 7f705cd9..c5d46a08 100644
--- a/.github/workflows/update-flake.yml
+++ b/.github/workflows/update-flake.yml
@@ -6,6 +6,10 @@ on:
     - cron: "0 0 1 * *"
   workflow_dispatch:
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   flake-update:
     runs-on: ubuntu-24.04