diff --git a/.github/workflows/claude.yml b/.github/workflows/claude.yml
index 94d50c5..e757d2d 100644
--- a/.github/workflows/claude.yml
+++ b/.github/workflows/claude.yml
@@ -35,7 +35,7 @@ jobs:
           fetch-depth: 0
 
       - name: Run Claude Code
-        uses: anthropics/claude-code-action@v1
+        uses: anthropics/claude-code-action@536f2c32a39763739000b0e1ac69ca2647d97ce9 # v1.0.170
         with:
           claude_code_oauth_token: ${{ secrets.claude_code_oauth_token }}
           github_token: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/code-review.yml b/.github/workflows/code-review.yml
index ba57038..0042f65 100644
--- a/.github/workflows/code-review.yml
+++ b/.github/workflows/code-review.yml
@@ -81,7 +81,7 @@ jobs:
             core.setOutput('check_run_id', check.data.id);
 
       - name: Claude Code Review
-        uses: anthropics/claude-code-action@v1
+        uses: anthropics/claude-code-action@536f2c32a39763739000b0e1ac69ca2647d97ce9 # v1.0.170
         with:
           claude_code_oauth_token: ${{ secrets.claude_code_oauth_token }}
           github_token: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/issue-followup.yml b/.github/workflows/issue-followup.yml
index 96b76a1..116fe48 100644
--- a/.github/workflows/issue-followup.yml
+++ b/.github/workflows/issue-followup.yml
@@ -44,7 +44,7 @@ jobs:
           fetch-depth: 0
 
       - name: Process Follow-up
-        uses: anthropics/claude-code-action@v1
+        uses: anthropics/claude-code-action@536f2c32a39763739000b0e1ac69ca2647d97ce9 # v1.0.170
         env:
           LINEAR_API_TOKEN:
             ${{ secrets.linear_api_token || secrets.LINEAR_API_TOKEN }}
diff --git a/.github/workflows/issue-implement.yml b/.github/workflows/issue-implement.yml
index a06c8d1..0e81f56 100644
--- a/.github/workflows/issue-implement.yml
+++ b/.github/workflows/issue-implement.yml
@@ -44,7 +44,7 @@ jobs:
           fetch-depth: 0
 
       - name: Implement Issue
-        uses: anthropics/claude-code-action@v1
+        uses: anthropics/claude-code-action@536f2c32a39763739000b0e1ac69ca2647d97ce9 # v1.0.170
         env:
           LINEAR_API_TOKEN:
             ${{ secrets.linear_api_token || secrets.LINEAR_API_TOKEN }}
diff --git a/.github/workflows/issue-triage.yml b/.github/workflows/issue-triage.yml
index 09188b2..6836c8c 100644
--- a/.github/workflows/issue-triage.yml
+++ b/.github/workflows/issue-triage.yml
@@ -43,7 +43,7 @@ jobs:
           fetch-depth: 0
 
       - name: Triage Issue
-        uses: anthropics/claude-code-action@v1
+        uses: anthropics/claude-code-action@536f2c32a39763739000b0e1ac69ca2647d97ce9 # v1.0.170
         env:
           LINEAR_API_TOKEN:
             ${{ secrets.linear_api_token || secrets.LINEAR_API_TOKEN }}