diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ae984ca4b0..ab39ab0686 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -118,7 +118,7 @@ jobs:
       uses: actions/setup-node@v1
       with:
         node-version: ${{ matrix.node-version }}
-    - run: sudo docker run --name mongo -d -p 27017:27017 mongo
+    - run: sudo docker run --name mongo -d -p 27017:27017 mongo:4.2
     - run: cp config.json.example config.json
     - name: npm install
       run: |
@@ -141,7 +141,7 @@ jobs:
       uses: actions/setup-node@v1
       with:
         node-version: ${{ matrix.node-version }}
-    - run: sudo docker run --name mongo -d -p 27017:27017 mongo
+    - run: sudo docker run --name mongo -d -p 27017:27017 mongo:4.2
     - run: cp config.json.example config.json
     - name: npm install
       run: |
@@ -164,7 +164,7 @@ jobs:
       uses: actions/setup-node@v1
       with:
         node-version: ${{ matrix.node-version }}
-    - run: sudo docker run --name mongo -d -p 27017:27017 mongo
+    - run: sudo docker run --name mongo -d -p 27017:27017 mongo:4.2
     - run: cp config.json.example config.json
     - name: npm install
       run: |
diff --git a/migrations/groups/reconcile-group-plan-members.js b/migrations/groups/reconcile-group-plan-members.js
index c7f5323608..17dedb2160 100644
--- a/migrations/groups/reconcile-group-plan-members.js
+++ b/migrations/groups/reconcile-group-plan-members.js
@@ -45,7 +45,7 @@ async function fixGroupPlanMembers () {
     pause();
     groupPlanCount += 1;
 
-    const canonicalMemberCount = await dbUsers.count(
+    const canonicalMemberCount = await dbUsers.countDocuments(
       {
         $or:
           [
diff --git a/website/server/libs/groupTasks.js b/website/server/libs/groupTasks.js
index 9bae66408f..e6d7df0605 100644
--- a/website/server/libs/groupTasks.js
+++ b/website/server/libs/groupTasks.js
@@ -24,13 +24,13 @@ async function _deleteUnfinishedTasks (groupMemberTask) {
 async function _evaluateAllAssignedCompletion (masterTask) {
   let completions;
   if (masterTask.group.approval && masterTask.group.approval.required) {
-    completions = await Tasks.Task.count({
+    completions = await Tasks.Task.countDocuments({
       'group.taskId': masterTask._id,
       'group.approval.approved': true,
     }).exec();
     completions += 1;
   } else {
-    completions = await Tasks.Task.count({
+    completions = await Tasks.Task.countDocuments({
       'group.taskId': masterTask._id,
       completed: true,
     }).exec();
diff --git a/website/server/models/group.js b/website/server/models/group.js
index f9548d994f..237c6f6989 100644
--- a/website/server/models/group.js
+++ b/website/server/models/group.js
@@ -482,7 +482,7 @@ schema.statics.validateInvitations = async function getInvitationErr (invites, r
     const query = {};
     query['invitations.party.id'] = group._id;
     // @TODO invitations are now stored like this: `'invitations.parties': []`
-    const groupInvites = await User.count(query).exec();
+    const groupInvites = await User.countDocuments(query).exec();
     memberCount += groupInvites;
 
     // Counting the members that are going to be invited by email and uuids
@@ -537,7 +537,7 @@ schema.methods.getMemberCount = async function getMemberCount () {
     query = { 'party._id': this._id };
   }
 
-  return User.count(query).exec();
+  return User.countDocuments(query).exec();
 };
 
 schema.methods.sendChat = function sendChat (options = {}) {
@@ -1743,7 +1743,7 @@ export const model = mongoose.model('Group', schema);
 // initialize tavern if !exists (fresh installs)
 // do not run when testing as it's handled by the tests and can easily cause a race condition
 if (!nconf.get('IS_TEST')) {
-  model.count({ _id: TAVERN_ID }, (err, ct) => {
+  model.countDocuments({ _id: TAVERN_ID }, (err, ct) => {
     if (err) throw err;
     if (ct > 0) return;
     new model({ // eslint-disable-line new-cap