diff --git a/package-lock.json b/package-lock.json
index 5451883..e238de7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1440,12 +1440,49 @@
         "eslint-plugin-react": "^7.11.1"
       }
     },
+    "@types/chai": {
+      "version": "4.1.7",
+      "resolved": "https://registry.npmjs.org/@types/chai/-/chai-4.1.7.tgz",
+      "integrity": "sha512-2Y8uPt0/jwjhQ6EiluT0XCri1Dbplr0ZxfFXUz+ye13gaqE8u5gL5ppao1JrUYr9cIip5S6MvQzBS7Kke7U9VA==",
+      "dev": true
+    },
+    "@types/chai-as-promised": {
+      "version": "7.1.0",
+      "resolved": "https://registry.npmjs.org/@types/chai-as-promised/-/chai-as-promised-7.1.0.tgz",
+      "integrity": "sha512-MFiW54UOSt+f2bRw8J7LgQeIvE/9b4oGvwU7XW30S9QGAiHGnU/fmiOprsyMkdmH2rl8xSPc0/yrQw8juXU6bQ==",
+      "dev": true,
+      "requires": {
+        "@types/chai": "*"
+      }
+    },
+    "@types/mocha": {
+      "version": "5.2.5",
+      "resolved": "https://registry.npmjs.org/@types/mocha/-/mocha-5.2.5.tgz",
+      "integrity": "sha512-lAVp+Kj54ui/vLUFxsJTMtWvZraZxum3w3Nwkble2dNuV5VnPA+Mi2oGX9XYJAaIvZi3tn3cbjS/qcJXRb6Bww==",
+      "dev": true
+    },
     "@types/node": {
       "version": "10.12.10",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-10.12.10.tgz",
       "integrity": "sha512-8xZEYckCbUVgK8Eg7lf5Iy4COKJ5uXlnIOnePN0WUwSQggy9tolM+tDJf7wMOnT/JT/W9xDYIaYggt3mRV2O5w==",
       "dev": true
     },
+    "@types/sinon": {
+      "version": "5.0.7",
+      "resolved": "https://registry.npmjs.org/@types/sinon/-/sinon-5.0.7.tgz",
+      "integrity": "sha512-opwMHufhUwkn/UUDk35LDbKJpA2VBsZT8WLU8NjayvRLGPxQkN+8XmfC2Xl35MAscBE8469koLLBjaI3XLEIww==",
+      "dev": true
+    },
+    "@types/sinon-chai": {
+      "version": "3.2.1",
+      "resolved": "https://registry.npmjs.org/@types/sinon-chai/-/sinon-chai-3.2.1.tgz",
+      "integrity": "sha512-6iO999tZP+1cixtz4jGaVS/aKRq2GYvFUhJzHWejYVUfTP0O98mGb0WrCaC9ARZVKfkm2FZrn3c0p3iaHfK+6A==",
+      "dev": true,
+      "requires": {
+        "@types/chai": "*",
+        "@types/sinon": "*"
+      }
+    },
     "JSONStream": {
       "version": "1.3.5",
       "resolved": "https://registry.npmjs.org/JSONStream/-/JSONStream-1.3.5.tgz",
diff --git a/package.json b/package.json
index 640ac46..a4a3d46 100644
--- a/package.json
+++ b/package.json
@@ -15,6 +15,11 @@
     "@commitlint/cli": "^7.0.0",
     "@commitlint/config-conventional": "^7.0.0",
     "@strv/eslint-config-javascript": "^9.0.0",
+    "@types/chai": "^4.1.7",
+    "@types/chai-as-promised": "^7.1.0",
+    "@types/mocha": "^5.2.5",
+    "@types/sinon": "^5.0.7",
+    "@types/sinon-chai": "^3.2.1",
     "babel-eslint": "^10.0.0",
     "chai": "^4.1.0",
     "chai-as-promised": "^7.1.1",