diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0b5cddc..c0fee2e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,6 +10,7 @@
 name: CI
 
 on:
+  merge_group:
   push:
     branches: [main, master, develop]
   pull_request:
diff --git a/.github/workflows/pr-validation.yml b/.github/workflows/pr-validation.yml
index d89b8c7..f71c959 100644
--- a/.github/workflows/pr-validation.yml
+++ b/.github/workflows/pr-validation.yml
@@ -8,6 +8,7 @@
 name: PR Validation
 
 on:
+  merge_group:
   pull_request:
     types: [opened, synchronize, reopened]
     branches:
@@ -17,7 +18,12 @@ on:
 
 # Cancel in-progress runs for same PR
 concurrency:
-  group: pr-validation-${{ github.event.pull_request.number }}
+  # #ASSUME github.event.pull_request.number is null under merge_group;
+  # fall back to github.ref (unique per merge-group ref) so a merge-group
+  # build never collides with, or is cancelled by, a PR build's group.
+  # #VERIFY confirm no cross-cancellation between a PR run and its
+  # corresponding merge-group run after the first live merge-queue pass.
+  group: pr-validation-${{ github.event.pull_request.number || github.ref }}
   cancel-in-progress: true
 
 permissions:
diff --git a/.github/workflows/reuse.yml b/.github/workflows/reuse.yml
index fd721d3..7b4ef0d 100644
--- a/.github/workflows/reuse.yml
+++ b/.github/workflows/reuse.yml
@@ -6,6 +6,7 @@
 name: REUSE Compliance
 
 on:
+  merge_group:
   # No paths filter: "Check REUSE Compliance" is a REQUIRED status check, so it
   # must report on every PR. A paths filter would skip the workflow on changes
   # that do not match (e.g. root-only files like renovate.json, since "**/*"
diff --git a/.github/workflows/security-analysis.yml b/.github/workflows/security-analysis.yml
index 438e58e..f5866db 100644
--- a/.github/workflows/security-analysis.yml
+++ b/.github/workflows/security-analysis.yml
@@ -10,6 +10,7 @@
 name: Security Analysis
 
 "on":
+  merge_group:
   push:
     branches: [main, master]
   pull_request: