diff --git a/.github/workflows/membrowse-comment.yml b/.github/workflows/membrowse-comment.yml
index f8ae6dc54f..2c6e9462ff 100644
--- a/.github/workflows/membrowse-comment.yml
+++ b/.github/workflows/membrowse-comment.yml
@@ -24,7 +24,9 @@ jobs:
 
       - name: Post Membrowse PR comment
         if: ${{ env.MEMBROWSE_API_KEY != '' }}
-        uses: membrowse/membrowse-action/comment-action@v1
+        # Pinned to a full commit SHA, same rationale as the report
+        # workflow. v1.2.15.
+        uses: membrowse/membrowse-action/comment-action@34719bdb04722be5cbe9c1d6df4a1567ae98238d
         with:
           api_key: ${{ secrets.MEMBROWSE_API_KEY }}
           commit: ${{ github.event.workflow_run.head_sha }}
diff --git a/.github/workflows/membrowse-onboard.yml b/.github/workflows/membrowse-onboard.yml
index 4cba2fa7d0..6351fcd339 100644
--- a/.github/workflows/membrowse-onboard.yml
+++ b/.github/workflows/membrowse-onboard.yml
@@ -50,7 +50,9 @@ jobs:
           ghcr-debs-tag: ${{ matrix.ghcr_tag }}
 
       - name: Run Membrowse Onboard Action
-        uses: membrowse/membrowse-action/onboard-action@v1
+        # Pinned to a full commit SHA, same rationale as the report
+        # workflow. v1.2.15.
+        uses: membrowse/membrowse-action/onboard-action@34719bdb04722be5cbe9c1d6df4a1567ae98238d
         with:
           target_name: ${{ matrix.target_name }}
           num_commits: ${{ github.event.inputs.num_commits }}
diff --git a/.github/workflows/membrowse-report.yml b/.github/workflows/membrowse-report.yml
index f7308819cd..2cc6f181a0 100644
--- a/.github/workflows/membrowse-report.yml
+++ b/.github/workflows/membrowse-report.yml
@@ -97,7 +97,9 @@ jobs:
 
       - name: Run Membrowse PR Action
         id: analyze
-        uses: membrowse/membrowse-action@v1
+        # Pinned to a full commit SHA so a moved v1 tag cannot break or
+        # swap the action out from under this job. v1.2.15.
+        uses: membrowse/membrowse-action@34719bdb04722be5cbe9c1d6df4a1567ae98238d
         with:
           target_name: ${{ matrix.target_name }}
           elf: ${{ needs.check-changes.outputs.needs_build == 'true' && matrix.elf || '' }}