diff --git a/apps/backend/__tests__/auth/test-auth.js b/apps/backend/__tests__/auth/test-auth.js
index dbc143d9..aa72c35c 100644
--- a/apps/backend/__tests__/auth/test-auth.js
+++ b/apps/backend/__tests__/auth/test-auth.js
@@ -120,7 +120,7 @@ describe('Test authentication ', () => {
 
         let updatedData = await mongoose
             .model(STEP_KEY)
-            .findOne({ _id: mongoose.Types.ObjectId(patientID) });
+            .findOne({ _id: new mongoose.Types.ObjectId(patientID) });
         updatedData = updatedData.toObject();
         updatedData._id = updatedData._id.toString();
 
diff --git a/apps/backend/__tests__/mock-data/patients-mock-data.js b/apps/backend/__tests__/mock-data/patients-mock-data.js
index 18dad270..219c4a2d 100644
--- a/apps/backend/__tests__/mock-data/patients-mock-data.js
+++ b/apps/backend/__tests__/mock-data/patients-mock-data.js
@@ -20,7 +20,7 @@ module.exports.POST_PATIENT_MINIMAL_REQUEST = {
 };
 
 module.exports.POST_IMMUTABLE_PATIENT_DATA = {
-    _id: mongoose.Types.ObjectId(),
+    _id: new mongoose.Types.ObjectId(),
     lastEdited: new Date('2000-12-02T01:17:55.181Z'),
     lastEditedBy: 'Tickle Me Elmo',
     __v: 1,
@@ -76,8 +76,8 @@ module.exports.DEFAULT_STEP_DATA = {
 };
 
 module.exports.POST_IMMUTABLE_STEP_DATA = {
-    _id: mongoose.Types.ObjectId(),
-    patientId: mongoose.Types.ObjectId(),
+    _id: new mongoose.Types.ObjectId(),
+    patientId: new mongoose.Types.ObjectId(),
     lastEdited: new Date('2000-12-02T01:17:55.181Z'),
     lastEditedBy: 'Tickle Me Elmo',
     __v: 1,
diff --git a/apps/backend/__tests__/routes/patients/test-patients-id.js b/apps/backend/__tests__/routes/patients/test-patients-id.js
index b7bc4691..96bc453d 100644
--- a/apps/backend/__tests__/routes/patients/test-patients-id.js
+++ b/apps/backend/__tests__/routes/patients/test-patients-id.js
@@ -61,7 +61,7 @@ describe('PUT /patients/:id', () => {
         // Query for ids must be done as an ObjectId
         let updatedData = await mongoose
             .model(STEP_KEY)
-            .findOne({ _id: mongoose.Types.ObjectId(patientID) });
+            .findOne({ _id: new mongoose.Types.ObjectId(patientID) });
         updatedData = updatedData.toObject();
         updatedData._id = updatedData._id.toString();
 
@@ -90,7 +90,7 @@ describe('PUT /patients/:id', () => {
 
         let updatedData = await mongoose
             .model(STEP_KEY)
-            .findOne({ _id: mongoose.Types.ObjectId(patientID) });
+            .findOne({ _id: new mongoose.Types.ObjectId(patientID) });
         updatedData = updatedData.toObject();
         updatedData._id = updatedData._id.toString();
         expectStrictEqualWithTimestampOrdering(
diff --git a/apps/backend/__tests__/routes/patients/test-put-patients-id.js b/apps/backend/__tests__/routes/patients/test-put-patients-id.js
index 0bedd8b1..8d909ac9 100644
--- a/apps/backend/__tests__/routes/patients/test-put-patients-id.js
+++ b/apps/backend/__tests__/routes/patients/test-put-patients-id.js
@@ -103,7 +103,7 @@ describe('PUT /patients/:id', () => {
 
     const getPatientFromDB = async () => {
         const result = await models.Patient.findOne({
-            _id: mongoose.Types.ObjectId(PATIENT_ID),
+            _id: new mongoose.Types.ObjectId(PATIENT_ID),
         });
         return result.toObject();
     };
diff --git a/apps/backend/__tests__/routes/roles/test-put-roles-roleid.js b/apps/backend/__tests__/routes/roles/test-put-roles-roleid.js
index 4ff99756..d977cc29 100644
--- a/apps/backend/__tests__/routes/roles/test-put-roles-roleid.js
+++ b/apps/backend/__tests__/routes/roles/test-put-roles-roleid.js
@@ -88,7 +88,7 @@ describe('PUT /roles/:roleid', () => {
 
     const getRoleFromDB = async (roleId) => {
         const result = await models.Role.findOne({
-            _id: mongoose.Types.ObjectId(roleId),
+            _id: new mongoose.Types.ObjectId(roleId),
         });
         return result.toObject();
     };
diff --git a/scripts/generate-db-data.js b/scripts/generate-db-data.js
index 9260b5e3..7781acd1 100644
--- a/scripts/generate-db-data.js
+++ b/scripts/generate-db-data.js
@@ -36,7 +36,7 @@ const generatePatients = (numPatients) => {
 const generatePatient = () => {
     const patient = {};
     patient.firstName = faker.name.firstName();
-    patient._id = mongoose.Types.ObjectId();
+    patient._id = new mongoose.Types.ObjectId();
 
     if (getRandomInt(2)) patient.fathersName = faker.name.firstName();