diff --git a/package-lock.json b/package-lock.json
index 807fabd..946ece6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -905,7 +905,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -1320,7 +1321,8 @@
         "safe-buffer": {
           "version": "5.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -1376,6 +1378,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -1419,12 +1422,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
@@ -3879,9 +3884,9 @@
       "dev": true
     },
     "typescript": {
-      "version": "3.1.6",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.1.6.tgz",
-      "integrity": "sha512-tDMYfVtvpb96msS1lDX9MEdHrW4yOuZ4Kdc4Him9oU796XldPYF/t2+uKoX0BBa0hXXwDlqYQbXY5Rzjzc5hBA==",
+      "version": "3.9.6",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.9.6.tgz",
+      "integrity": "sha512-Pspx3oKAPJtjNwE92YS05HQoY7z2SFyOpHo9MqJor3BXAGNaPUs83CuVp9VISFkSjyRfiTpmKuAYGJB7S7hOxw==",
       "dev": true
     },
     "union-value": {
diff --git a/package.json b/package.json
index 20fdd3c..5cdf881 100644
--- a/package.json
+++ b/package.json
@@ -31,6 +31,6 @@
     "mocha": "5.2.0",
     "puppeteer": "1.10.0",
     "sinon": "7.1.1",
-    "typescript": "3.1.6"
+    "typescript": "3.9.6"
   }
 }