diff --git a/cloud-sql/postgres/knex/package.json b/cloud-sql/postgres/knex/package.json
index f4a2af9bd6..614c4ee92a 100644
--- a/cloud-sql/postgres/knex/package.json
+++ b/cloud-sql/postgres/knex/package.json
@@ -13,7 +13,7 @@
     "node": ">=8"
   },
   "scripts": {
-    "unit-test": "ava --verbose test/*.test.js",
+    "unit-test": "mocha test/*.test.js --timeout=60000 --exit",
     "start-proxy": "! pgrep cloud_sql_proxy > /dev/null && cloud_sql_proxy -dir=/cloudsql -instances=$CLOUD_SQL_INSTANCE_NAME &",
     "system-test": "repo-tools test app -- server.js",
     "system-test-proxy": "npm run start-proxy; npm run system-test",
@@ -30,8 +30,8 @@
     "winston": "^3.1.0"
   },
   "devDependencies": {
-    "@google-cloud/nodejs-repo-tools": "^3.2.0",
-    "ava": "^0.25.0",
+    "@google-cloud/nodejs-repo-tools": "3.2.0",
+    "mocha": "^6.0.0",
     "proxyquire": "^2.1.0",
     "supertest": "^4.0.0",
     "sinon": "^7.1.1"
diff --git a/cloud-sql/postgres/knex/test/createTable.test.js b/cloud-sql/postgres/knex/test/createTable.test.js
index 2cfda1654f..8e054a42af 100644
--- a/cloud-sql/postgres/knex/test/createTable.test.js
+++ b/cloud-sql/postgres/knex/test/createTable.test.js
@@ -15,15 +15,15 @@
 
 'use strict';
 
-const test = require(`ava`);
-const path = require(`path`);
-const proxyquire = require(`proxyquire`).noPreserveCache();
-const sinon = require(`sinon`);
-const tools = require(`@google-cloud/nodejs-repo-tools`);
+const assert = require('assert');
+const path = require('path');
+const proxyquire = require('proxyquire').noPreserveCache();
+const sinon = require('sinon');
+const tools = require('@google-cloud/nodejs-repo-tools');
 
-const SAMPLE_PATH = path.join(__dirname, `../createTables.js`);
+const SAMPLE_PATH = path.join(__dirname, '../createTable.js');
 
-const exampleConfig = [`user`, `password`, `database`];
+const exampleConfig = ['user', 'password', 'database'];
 
 function getSample() {
   const configMock = exampleConfig;
@@ -58,10 +58,10 @@ function getSample() {
   };
 }
 
-test.beforeEach(tools.stubConsole);
-test.afterEach.always(tools.restoreConsole);
+beforeEach(tools.stubConsole);
+afterEach(tools.restoreConsole);
 
-test.cb.serial(`should create a table`, t => {
+it('should create a table', async () => {
   const sample = getSample();
   const expectedResult = `Successfully created 'votes' table.`;
 
@@ -70,30 +70,34 @@ test.cb.serial(`should create a table`, t => {
     prompt: sample.mocks.prompt,
   });
 
-  t.true(sample.mocks.prompt.start.calledOnce);
-  t.true(sample.mocks.prompt.get.calledOnce);
-  t.deepEqual(sample.mocks.prompt.get.firstCall.args[0], exampleConfig);
-
-  setTimeout(() => {
-    t.true(sample.mocks.Knex.calledOnce);
-    t.deepEqual(sample.mocks.Knex.firstCall.args, [
-      {
-        client: 'pg',
-        connection: exampleConfig,
-      },
-    ]);
-
-    t.true(sample.mocks.knex.schema.createTable.calledOnce);
-    t.is(sample.mocks.knex.schema.createTable.firstCall.args[0], 'votes');
-
-    t.true(console.log.calledWith(expectedResult));
-    t.true(sample.mocks.knex.destroy.calledOnce);
-    t.end();
-  }, 10);
+  assert.ok(sample.mocks.prompt.start.calledOnce);
+  assert.ok(sample.mocks.prompt.get.calledOnce);
+  assert.deepStrictEqual(
+    sample.mocks.prompt.get.firstCall.args[0],
+    exampleConfig
+  );
+
+  await new Promise(r => setTimeout(r, 10));
+  assert.ok(sample.mocks.Knex.calledOnce);
+  assert.deepStrictEqual(sample.mocks.Knex.firstCall.args, [
+    {
+      client: 'pg',
+      connection: exampleConfig,
+    },
+  ]);
+
+  assert.ok(sample.mocks.knex.schema.createTable.calledOnce);
+  assert.strictEqual(
+    sample.mocks.knex.schema.createTable.firstCall.args[0],
+    'votes'
+  );
+
+  assert.ok(console.log.calledWith(expectedResult));
+  assert.ok(sample.mocks.knex.destroy.calledOnce);
 });
 
-test.cb.serial(`should handle prompt error`, t => {
-  const error = new Error(`error`);
+it('should handle prompt error', async () => {
+  const error = new Error('error');
   const sample = getSample();
   sample.mocks.prompt.get = sinon.stub().yields(error);
 
@@ -102,16 +106,14 @@ test.cb.serial(`should handle prompt error`, t => {
     prompt: sample.mocks.prompt,
   });
 
-  setTimeout(() => {
-    t.true(console.error.calledOnce);
-    t.true(console.error.calledWith(error));
-    t.true(sample.mocks.Knex.notCalled);
-    t.end();
-  }, 10);
+  await new Promise(r => setTimeout(r, 10));
+  assert.ok(console.error.calledOnce);
+  assert.ok(console.error.calledWith(error));
+  assert.ok(sample.mocks.Knex.notCalled);
 });
 
-test.cb.serial(`should handle knex creation error`, t => {
-  const error = new Error(`error`);
+it('should handle knex creation error', async () => {
+  const error = new Error('error');
   const sample = getSample();
   sample.mocks.knex.schema.createTable = sinon
     .stub()
@@ -122,10 +124,8 @@ test.cb.serial(`should handle knex creation error`, t => {
     prompt: sample.mocks.prompt,
   });
 
-  setTimeout(() => {
-    t.true(console.error.calledOnce);
-    t.true(console.error.calledWith(`Failed to create 'votes' table:`, error));
-    t.true(sample.mocks.knex.destroy.calledOnce);
-    t.end();
-  }, 10);
+  await new Promise(r => setTimeout(r, 10));
+  assert.ok(console.error.calledOnce);
+  assert.ok(console.error.calledWith(`Failed to create 'votes' table:`, error));
+  assert.ok(sample.mocks.knex.destroy.calledOnce);
 });
diff --git a/cloud-sql/postgres/knex/test/server.test.js b/cloud-sql/postgres/knex/test/server.test.js
index ea2dfa8e4e..a7e7f26cc8 100644
--- a/cloud-sql/postgres/knex/test/server.test.js
+++ b/cloud-sql/postgres/knex/test/server.test.js
@@ -15,19 +15,19 @@
 
 'use strict';
 
-const express = require(`express`);
-const path = require(`path`);
-const proxyquire = require(`proxyquire`).noCallThru();
-const request = require(`supertest`);
-const sinon = require(`sinon`);
-const test = require(`ava`);
-const tools = require(`@google-cloud/nodejs-repo-tools`);
+const express = require('express');
+const path = require('path');
+const proxyquire = require('proxyquire').noCallThru();
+const request = require('supertest');
+const sinon = require('sinon');
+const assert = require('assert');
+const tools = require('@google-cloud/nodejs-repo-tools');
 
-const SAMPLE_PATH = path.join(__dirname, `../server.js`);
+const SAMPLE_PATH = path.join(__dirname, '../server.js');
 
 function getSample() {
   const testApp = express();
-  sinon.stub(testApp, `listen`).yields();
+  sinon.stub(testApp, 'listen').yields();
   const expressMock = sinon.stub().returns(testApp);
   const timestamp = new Date();
   const resultsMock = [
@@ -75,15 +75,15 @@ function getSample() {
   };
 }
 
-test.beforeEach(tools.stubConsole);
-test.afterEach.always(tools.restoreConsole);
+beforeEach(tools.stubConsole);
+afterEach(tools.restoreConsole);
 
-test(`should set up sample in Postgres`, t => {
+it('should set up sample in Postgres', () => {
   const sample = getSample();
 
-  t.true(sample.mocks.express.calledOnce);
-  t.true(sample.mocks.Knex.calledOnce);
-  t.deepEqual(sample.mocks.Knex.firstCall.args, [
+  assert.ok(sample.mocks.express.calledOnce);
+  assert.ok(sample.mocks.Knex.calledOnce);
+  assert.deepStrictEqual(sample.mocks.Knex.firstCall.args, [
     {
       client: 'pg',
       connection: {
@@ -95,30 +95,28 @@ test(`should set up sample in Postgres`, t => {
   ]);
 });
 
-test.cb(`should display the default page`, t => {
+it('should display the default page', async () => {
   const sample = getSample();
-  const expectedResult = `Tabs VS Spaces`;
+  const expectedResult = 'Tabs VS Spaces';
 
-  request(sample.app)
-    .get(`/`)
+  await request(sample.app)
+    .get('/')
     .expect(200)
     .expect(response => {
-      t.is(response.text, expectedResult);
-    })
-    .end(t.end);
+      assert.strictEqual(response.text, expectedResult);
+    });
 });
 
-test.cb(`should handle insert error`, t => {
+it('should handle insert error', async () => {
   const sample = getSample();
   const expectedResult = 'Invalid team specified';
 
   sample.mocks.knex.limit.returns(Promise.reject());
 
-  request(sample.app)
-    .post(`/`)
+  await request(sample.app)
+    .post('/')
     .expect(400)
     .expect(response => {
-      t.is(response.text.includes(expectedResult), true);
-    })
-    .end(t.end);
+      assert.ok(response.text.includes(expectedResult));
+    });
 });