diff --git a/package-lock.json b/package-lock.json
index 0461bf7bc..73f73f28e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1173,9 +1173,9 @@
       "dev": true
     },
     "typescript": {
-      "version": "3.1.1",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.1.1.tgz",
-      "integrity": "sha512-Veu0w4dTc/9wlWNf2jeRInNodKlcdLgemvPsrNpfu5Pq39sgfFjvIIgTsvUHCoLBnMhPoUA+tFxsXjU6VexVRQ==",
+      "version": "3.1.5",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.1.5.tgz",
+      "integrity": "sha512-muYNWV9j5+3mXoKD6oPONKuGUmYiFX14gfo9lWm9ZXRHOqVDQiB4q1CzFPbF4QLV2E9TZXH6oK55oQ94rn3PpA==",
       "dev": true
     },
     "ua-parser-js": {
diff --git a/package.json b/package.json
index d3d5eac27..9585ceca3 100644
--- a/package.json
+++ b/package.json
@@ -69,7 +69,7 @@
     "semver": "^5.1.0",
     "tslint": "^5.11.0",
     "tslint-config-standard": "^8.0.1",
-    "typescript": "^3.1.1"
+    "typescript": "^3.1.5"
   },
   "peerDependencies": {
     "typescript": ">=2.0"
diff --git a/src/index.spec.ts b/src/index.spec.ts
index db422c870..1803ed306 100644
--- a/src/index.spec.ts
+++ b/src/index.spec.ts
@@ -6,9 +6,10 @@ import ts = require('typescript')
 import proxyquire = require('proxyquire')
 import { register, VERSION } from './index'
 
-const testDir = join(__dirname, '../tests')
+const TEST_DIR = join(__dirname, '../tests')
 const EXEC_PATH = join(__dirname, '../dist/bin')
-const BIN_EXEC = `node "${EXEC_PATH}" --project "${testDir}/tsconfig.json"`
+const PROJECT = join(TEST_DIR, semver.gte(ts.version, '2.5.0') ? 'tsconfig.json5' : 'tsconfig.json')
+const BIN_EXEC = `node "${EXEC_PATH}" --project "${PROJECT}"`
 
 const SOURCE_MAP_REGEXP = /\/\/# sourceMappingURL=data:application\/json;charset=utf\-8;base64,[\w\+]+=*$/
 
@@ -33,7 +34,7 @@ describe('ts-node', function () {
 
     it('should register via cli', function (done) {
       exec(`node -r ../register hello-world.ts`, {
-        cwd: testDir
+        cwd: TEST_DIR
       }, function (err, stdout) {
         expect(err).to.equal(null)
         expect(stdout).to.equal('Hello, world!\n')
@@ -43,7 +44,7 @@ describe('ts-node', function () {
     })
 
     it('should execute cli with absolute path', function (done) {
-      exec(`${BIN_EXEC} "${join(testDir, 'hello-world')}"`, function (err, stdout) {
+      exec(`${BIN_EXEC} "${join(TEST_DIR, 'hello-world')}"`, function (err, stdout) {
         expect(err).to.equal(null)
         expect(stdout).to.equal('Hello, world!\n')
 
@@ -263,7 +264,7 @@ describe('ts-node', function () {
 
   describe('register', function () {
     register({
-      project: join(testDir, 'tsconfig.json'),
+      project: PROJECT,
       compilerOptions: {
         jsx: 'preserve'
       }
diff --git a/tests/tsconfig.json b/tests/tsconfig.json
index 12fb856f1..526a7e0bf 100644
--- a/tests/tsconfig.json
+++ b/tests/tsconfig.json
@@ -2,10 +2,9 @@
   "compilerOptions": {
     "jsx": "react",
     "noEmit": true,
-    // Global type definitions.
     "typeRoots": [
       "./typings",
-      "../node_modules/@types",
-    ],
+      "../node_modules/@types"
+    ]
   }
 }
diff --git a/tests/tsconfig.json5 b/tests/tsconfig.json5
new file mode 100644
index 000000000..12fb856f1
--- /dev/null
+++ b/tests/tsconfig.json5
@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "jsx": "react",
+    "noEmit": true,
+    // Global type definitions.
+    "typeRoots": [
+      "./typings",
+      "../node_modules/@types",
+    ],
+  }
+}