diff --git a/package.json b/package.json
index 3ed160a..30b8aa1 100644
--- a/package.json
+++ b/package.json
@@ -35,9 +35,6 @@
     "trailingComma": "es5"
   },
   "jest": {
-    "setupFiles": [
-      "<rootDir>/test/helpers.js"
-    ],
     "moduleFileExtensions": [
       "js",
       "ts"
diff --git a/src/rules/types.test.js b/src/rules/types.test.js
index f8cadd0..46aba0b 100644
--- a/src/rules/types.test.js
+++ b/src/rules/types.test.js
@@ -1,7 +1,65 @@
-/* global assertJSONBReport, assertTextReport, assertIdentityReport */
-
 import * as types from './types';
 
+const assertReport = (
+  mockReporter,
+  expectedRule,
+  expectedIdentifier,
+  expectedMessage,
+  expectedSuggestedMigration
+) => {
+  expect(mockReporter).toBeCalledWith(
+    expect.objectContaining({
+      rule: expectedRule,
+      identifier: expectedIdentifier,
+      message: expectedMessage,
+      suggestedMigration: expectedSuggestedMigration,
+    })
+  );
+};
+
+const assertJSONBReport = (
+  mockReporter,
+  expectedIdentifier,
+  expectedSuggestedMigration
+) => {
+  assertReport(
+    mockReporter,
+    'prefer-jsonb-to-json',
+    expectedIdentifier,
+    'Prefer JSONB to JSON types',
+    expectedSuggestedMigration
+  );
+};
+
+const assertTextReport = (
+  mockReporter,
+  expectedIdentifier,
+  expectedColumnType,
+  expectedSuggestedMigration
+) => {
+  assertReport(
+    mockReporter,
+    'prefer-text-to-varchar',
+    expectedIdentifier,
+    `Prefer text to ${expectedColumnType} types`,
+    expectedSuggestedMigration
+  );
+};
+
+const assertIdentityReport = (
+  mockReporter,
+  expectedIdentifier,
+  expectedSuggestedMigration
+) => {
+  assertReport(
+    mockReporter,
+    'prefer-identity-to-serial',
+    expectedIdentifier,
+    'Prefer IDENTITY to type SERIAL',
+    expectedSuggestedMigration
+  );
+};
+
 describe('types', () => {
   describe('prefer-jsonb-to-json', () => {
     it('no tables has no errors', () => {
diff --git a/test/helpers.js b/test/helpers.js
deleted file mode 100644
index 37d0833..0000000
--- a/test/helpers.js
+++ /dev/null
@@ -1,58 +0,0 @@
-/* global expect, assertReport */
-
-global.assertReport = (
-  mockReporter,
-  expectedRule,
-  expectedIdentifier,
-  expectedMessage,
-  expectedSuggestedMigration
-) => {
-  expect(mockReporter).toBeCalledWith(
-    expect.objectContaining({
-      rule: expectedRule,
-      identifier: expectedIdentifier,
-      message: expectedMessage,
-      suggestedMigration: expectedSuggestedMigration,
-    })
-  );
-};
-global.assertJSONBReport = (
-  mockReporter,
-  expectedIdentifier,
-  expectedSuggestedMigration
-) => {
-  assertReport(
-    mockReporter,
-    'prefer-jsonb-to-json',
-    expectedIdentifier,
-    'Prefer JSONB to JSON types',
-    expectedSuggestedMigration
-  );
-};
-global.assertTextReport = (
-  mockReporter,
-  expectedIdentifier,
-  expectedColumnType,
-  expectedSuggestedMigration
-) => {
-  assertReport(
-    mockReporter,
-    'prefer-text-to-varchar',
-    expectedIdentifier,
-    `Prefer text to ${expectedColumnType} types`,
-    expectedSuggestedMigration
-  );
-};
-global.assertIdentityReport = (
-  mockReporter,
-  expectedIdentifier,
-  expectedSuggestedMigration
-) => {
-  assertReport(
-    mockReporter,
-    'prefer-identity-to-serial',
-    expectedIdentifier,
-    'Prefer IDENTITY to type SERIAL',
-    expectedSuggestedMigration
-  );
-};