diff --git a/lib/Page.js b/lib/Page.js
index 3f5220d1..0b1233e9 100644
--- a/lib/Page.js
+++ b/lib/Page.js
@@ -33,8 +33,9 @@ class Page extends EventEmitter {
             client.send('Runtime.enable', {}),
             client.send('Security.enable', {}),
         ]);
-        var screenDPI = await helpers.evaluate(client, () => window.devicePixelRatio, []);
-        var page = new Page(client, screenDPI.result.value);
+        var expression = helpers.evaluationString(() => window.devicePixelRatio, []);
+        var {result:{value: screenDPI}} = await client.send('Runtime.evaluate', { expression, returnByValue: true });
+        var page = new Page(client, screenDPI);
         // Initialize default page size.
         await page.setViewportSize({width: 400, height: 300});
         return page;
@@ -108,8 +109,8 @@ class Page extends EventEmitter {
      * @return {!Promise}
      */
     async injectFile(filePath) {
-        var code = fs.readFileSync(filePath, 'utf8');
-        await helpers.evaluateText(this._client, code, false /* awaitPromise */);
+        var expression = fs.readFileSync(filePath, 'utf8');
+        await this._client.send('Runtime.evaluate', { expression, returnByValue: true });
     }
 
     /**
@@ -125,11 +126,11 @@ class Page extends EventEmitter {
 
         var sourceURL = '__in_page_callback__' + name;
         this._sourceURLToPageCallback.set(sourceURL, new InPageCallback(name, callback));
-        var text = helpers.evaluationString(inPageCallback, [name], false /* wrapInPromise */, sourceURL);
+        var expression = helpers.evaluationString(inPageCallback, [name], false /* wrapInPromise */, sourceURL);
         await Promise.all([
             this._client.send('Debugger.enable', {}),
-            this._client.send('Page.addScriptToEvaluateOnLoad', { scriptSource: text }),
-            helpers.evaluateText(this._client, text, false /* awaitPromise */)
+            this._client.send('Page.addScriptToEvaluateOnLoad', { scriptSource: expression }),
+            this._client.send('Runtime.evaluate', { expression, returnByValue: true })
         ]);
 
         function inPageCallback(callbackName) {
diff --git a/lib/helpers.js b/lib/helpers.js
index b3419ab6..ddd764db 100644
--- a/lib/helpers.js
+++ b/lib/helpers.js
@@ -15,66 +15,11 @@
  */
 
 var helpers = module.exports = {
-    /**
-     * @param {!Connection} client
-     * @param {string} url
-     * @return {!Promise<?Object>}
-     */
-    waitForScriptWithURL: function(client, url) {
-        var fulfill;
-        var promise = new Promise(x => fulfill = x);
-        client.on('Debugger.scriptParsed', onScriptParsed);
-        client.on('Debugger.scriptFailedToParse', onScriptFailedToParse);
-        return promise;
-
-        function onScriptParsed(event) {
-            if (event.url !== url)
-                return;
-            client.removeListener('Debugger.scriptParsed', onScriptParsed);
-            client.removeListener('Debugger.scriptFailedToParse', onScriptFailedToParse);
-            fulfill(event);
-        }
-
-        function onScriptFailedToParse(event) {
-            if (event.url !== url)
-                return;
-            client.removeListener('Debugger.scriptParsed', onScriptParsed);
-            client.removeListener('Debugger.scriptFailedToParse', onScriptFailedToParse);
-            fulfill(null);
-        }
-    },
-
-    /**
-     * @param {!Connection} client
-     * @param {function()} fun
-     * @param {!Array<*>} args
-     * @param {boolean} awaitPromise
-     * @param {string=} sourceURL
-     * @return {!Promise<!Object>}
-     */
-    evaluate: function(client, fun, args, awaitPromise, sourceURL) {
-        var code = helpers.evaluationString(fun, args, awaitPromise, sourceURL);
-        return helpers.evaluateText(client, code, awaitPromise);
-    },
-
-    /**
-     * @param {!Connection} client
-     * @param {string} text
-     * @param {boolean} awaitPromise
-     * @return {!Promise<!Object>}
-     */
-    evaluateText: function(client, text, awaitPromise) {
-        return client.send('Runtime.evaluate', {
-            expression: text,
-            awaitPromise: awaitPromise,
-            returnByValue: true
-        });
-    },
 
     /**
      * @param {function()} fun
      * @param {!Array<*>} args
-     * @param {boolean} wrapInPromise
+     * @param {boolean=} wrapInPromise
      * @param {string=} sourceURL
      * @return {string}
      */