diff --git a/packages/datadog-plugin-mongoose/test/index.spec.js b/packages/datadog-plugin-mongoose/test/index.spec.js
index 35092db5aa8..3ca538a2b5f 100644
--- a/packages/datadog-plugin-mongoose/test/index.spec.js
+++ b/packages/datadog-plugin-mongoose/test/index.spec.js
@@ -3,9 +3,9 @@
 const semver = require('semver')
 const agent = require('../../dd-trace/test/plugins/agent')
 const { NODE_MAJOR } = require('../../../version')
+const id = require('../../dd-trace/src/id')
 
 describe('Plugin', () => {
-  let id
   let tracer
   let dbName
 
@@ -23,7 +23,8 @@ describe('Plugin', () => {
       function connect () {
         // mongoose.connect('mongodb://username:password@host:port/database?options...');
         // actually the first part of the path is the dbName and not the collection
-        mongoose.connect(`mongodb://localhost:27017/${dbName}`, {
+        return mongoose.connect(`mongodb://localhost:27017/${dbName}`, {
+          bufferCommands: false,
           useNewUrlParser: true,
           useUnifiedTopology: true
         })
@@ -33,25 +34,14 @@ describe('Plugin', () => {
         return agent.load(['mongodb-core'])
       })
 
-      before(() => {
-        id = require('../../dd-trace/src/id')
+      before(async () => {
         tracer = require('../../dd-trace')
 
-        dbName = id().toString()
-
         mongoose = require(`../../../versions/mongoose@${version}`).get()
 
-        connect()
-
-        withPeerService(
-          () => tracer,
-          'mongodb-core',
-          (done) => {
-            const PeerCat = mongoose.model('PeerCat', { name: String })
-            new PeerCat({ name: 'PeerCat' }).save().catch(done)
-            done()
-          },
-          'db', 'peer.service')
+        dbName = id().toString()
+
+        await connect()
       })
 
       after(() => {
@@ -62,6 +52,15 @@ describe('Plugin', () => {
         return agent.close({ ritmReset: false })
       })
 
+      withPeerService(
+        () => tracer,
+        'mongodb-core',
+        (done) => {
+          const PeerCat = mongoose.model('PeerCat', { name: String })
+          new PeerCat({ name: 'PeerCat' }).save().catch(done)
+        },
+        () => dbName, 'peer.service')
+
       it('should propagate context with write operations', () => {
         const Cat = mongoose.model('Cat1', { name: String })
 
diff --git a/packages/dd-trace/test/setup/mocha.js b/packages/dd-trace/test/setup/mocha.js
index 950d96bfda4..2abf0b86c3b 100644
--- a/packages/dd-trace/test/setup/mocha.js
+++ b/packages/dd-trace/test/setup/mocha.js
@@ -131,7 +131,7 @@ function withPeerService (tracer, pluginName, spanGenerationFn, service, service
       agent
         .use(traces => {
           const span = traces[0][0]
-          expect(span.meta).to.have.property('peer.service', service)
+          expect(span.meta).to.have.property('peer.service', typeof service === 'function' ? service() : service)
           expect(span.meta).to.have.property('_dd.peer.service.source', serviceSource)
         })
         .then(done)