diff --git a/package.json b/package.json
index f07c136e8..4540f59f0 100644
--- a/package.json
+++ b/package.json
@@ -56,20 +56,20 @@
     "typescript": "~3.1.5"
   },
   "scripts": {
-    "codecov": "istanbul test ./node_modules/mocha/bin/_mocha -- build/test --reporter spec --slow 500 && ./node_modules/codecov/bin/codecov",
+    "codecov": "nyc mocha build/test --reporter spec --slow 500 && codecov",
     "docs": "echo no docs 📗",
     "gen-parser": "pegjs lib/path_template_parser.pegjs",
     "test": "npm run test-only",
-    "test-only": "istanbul test ./node_modules/mocha/bin/_mocha -- build/test --reporter spec --slow 500",
+    "test-only": "nyc mocha build/test --reporter spec --slow 500",
     "publish-gh-pages": "bash ./publish-gh-pages.sh",
     "lint": "gts check",
     "clean": "gts clean",
-    "compile": "tsc -p . && cp src/operations_client_config.json build/src",
+    "compile": "tsc -p . && cp src/*.json build/src && cp src/*.js build/src",
     "fix": "gts fix",
     "prepare": "npm run compile",
     "pretest-only": "npm run compile",
     "posttest": "npm run lint",
-    "system-test": "nyc mocha --timeout 1200000 build/system-test/system.js",
+    "system-test": "nyc mocha --timeout 1200000 build/system-test",
     "samples-test": "echo no sample tests 😱"
   },
   "repository": "googleapis/gax-nodejs",
diff --git a/src/path_template_parser.ts b/src/path_template_parser.js
similarity index 99%
rename from src/path_template_parser.ts
rename to src/path_template_parser.js
index 7aa37bfe0..791a26007 100644
--- a/src/path_template_parser.ts
+++ b/src/path_template_parser.js
@@ -97,7 +97,7 @@ module.exports = (() => {
     let peg$savedPos = 0;
     const peg$posDetailsCache = [{line: 1, column: 1, seenCR: false}];
     let peg$maxFailPos = 0;
-    let peg$maxFailExpected: Array<{}> = [];
+    let peg$maxFailExpected = [];
     const peg$silentFails = 0;
     let peg$result;
 
diff --git a/test/api_callable.ts b/test/api_callable.ts
index cb5d64ead..ccdd8386a 100644
--- a/test/api_callable.ts
+++ b/test/api_callable.ts
@@ -33,7 +33,6 @@ import * as sinon from 'sinon';
 
 import * as gax from '../src/gax';
 import {GoogleError} from '../src/GoogleError';
-
 import * as utils from './utils';
 
 const fail = utils.fail;
@@ -45,8 +44,8 @@ const FAKE_STATUS_CODE_2 = (utils as any).FAKE_STATUS_CODE_1 + 1;
 
 describe('createApiCall', () => {
   it('calls api call', (done) => {
-    let deadlineArg;
-    function func(argument, metadata, options, callback) {
+    let deadlineArg: {};
+    function func(argument: {}, metadata: {}, options, callback) {
       deadlineArg = options.deadline;
       callback(null, argument);
     }
diff --git a/tsconfig.json b/tsconfig.json
index 1942ae08f..5dc9ad65f 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -3,8 +3,7 @@
   "compilerOptions": {
     "rootDir": ".",
     "outDir": "build",
-    "noImplicitAny": false,
-    "noImplicitThis": false
+    "noImplicitAny": false
   },
   "include": [
     "src/*.ts",