diff --git a/.gitea/workflows/run-tests.yaml b/.gitea/workflows/run-tests.yaml
index 6141330..68c459d 100644
--- a/.gitea/workflows/run-tests.yaml
+++ b/.gitea/workflows/run-tests.yaml
@@ -68,12 +68,14 @@ jobs:
         env:
           TEST_ENV_FILE: ./environment.test.env
           NODE_ENV: test
+          MONGOMS_VERSION: 4.4.28
         run: npm run test:integration:contract
 
       - name: Run Jest integration tests
         env:
           TEST_ENV_FILE: ./environment.test.env
           NODE_ENV: test
+          MONGOMS_VERSION: 4.4.28
         run: npm run test:integration:jest -- --ci
 
       - name: Upload Jest results
diff --git a/Development/server/tests/integration/jest.setup.js b/Development/server/tests/integration/jest.setup.js
index 6da01a3..3dbfc3f 100644
--- a/Development/server/tests/integration/jest.setup.js
+++ b/Development/server/tests/integration/jest.setup.js
@@ -20,6 +20,7 @@ const { MongoMemoryServer } = require('mongodb-memory-server');
 const mongoose = require('mongoose');
 
 let mongod = null;
+const MONGOMS_VERSION = process.env.MONGOMS_VERSION || '4.4.28';
 
 /**
  * Start the in-memory MongoDB server and connect mongoose.
@@ -28,7 +29,15 @@ let mongod = null;
 async function connectDB() {
   if (mongoose.connection.readyState !== 0) return; // already connected
 
-  mongod = await MongoMemoryServer.create();
+  try {
+    mongod = await MongoMemoryServer.create({
+      binary: { version: MONGOMS_VERSION },
+    });
+  } catch (error) {
+    error.message = `${error.message}\nFailed to start mongodb-memory-server with MongoDB ${MONGOMS_VERSION}. ` +
+      'If this runner lacks AVX support, keep MONGOMS_VERSION pinned to a 4.4.x release.';
+    throw error;
+  }
   const uri = mongod.getUri();
 
   mongoose.set('strictPopulate', false);
@@ -59,6 +68,9 @@ async function disconnectDB() {
  * Call this inside beforeEach() / afterEach() to keep tests isolated.
  */
 async function clearCollection(model) {
+  if (!model || typeof model.deleteMany !== 'function') {
+    throw new Error('clearCollection received an invalid model. Check that connectDB completed successfully before using test models.');
+  }
   await model.deleteMany({});
 }