diff --git a/.travis.yml b/.travis.yml
index a4248ca..1691060 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,6 +11,8 @@ script:
   - npm test
   - npm install --no-save typescript@2.4
   - npm test
+  - npm install --no-save typescript
+  - npm test
 cache:
   directories:
     - node_modules
diff --git a/README.md b/README.md
index 1abc0fc..91e16ac 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ espower-typescript
 
 ## TypeScript versions
 
-* espower-typescript v8.x uses TypeScript v2.2, v2.3 and v2.4
+* espower-typescript v8.x uses TypeScript from v2.2 to v2.5
 * espower-typescript v7.x uses TypeScript v2.1
 * espower-typescript v6.x uses TypeScript v2.0
 * espower-typescript v5.x uses TypeScript v1.8
diff --git a/package-lock.json b/package-lock.json
index 5ef2f68..399a9b5 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1422,9 +1422,9 @@
       "integrity": "sha1-7+fUEj2KxSr/9/QMfk3sUmYAj7Q="
     },
     "typescript": {
-      "version": "2.4.2",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-2.4.2.tgz",
-      "integrity": "sha1-+DlfhdRZJ2BnyYiqQYN6j4KHCEQ="
+      "version": "2.5.0",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-2.5.0.tgz",
+      "integrity": "sha1-YJiedMrZPCj+Nff3tB/psgWiVwE="
     },
     "typescript-simple": {
       "version": "8.0.3",
@@ -1432,6 +1432,13 @@
       "integrity": "sha512-rvmB8QIS5RwypAKT/kN7z2/90zN7iH8Q3EKcWtfDIIArYUut0KKmFyZn1gnWhcjL1jdF/ZDJVNPAVxmE9yPzGw==",
       "requires": {
         "typescript": "2.4.2"
+      },
+      "dependencies": {
+        "typescript": {
+          "version": "2.4.2",
+          "resolved": "https://registry.npmjs.org/typescript/-/typescript-2.4.2.tgz",
+          "integrity": "sha1-+DlfhdRZJ2BnyYiqQYN6j4KHCEQ="
+        }
       }
     },
     "ua-parser-js": {
diff --git a/package.json b/package.json
index 4f3af9e..f5ba89e 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,7 @@
   "dependencies": {
     "espower-source": "^2.0.0",
     "minimatch": "^3.0.3",
-    "typescript": "^2.4.2",
+    "typescript": "^2.2.1",
     "typescript-simple": "^8.0.3"
   },
   "devDependencies": {