diff --git a/index.js b/index.js
index f0ac06f..f827220 100644
--- a/index.js
+++ b/index.js
@@ -34,7 +34,7 @@ const path = require('path');
 const defaultDuration = 5;
 const defaultFPS = 60;
 const { overwriteRandom } = require('./lib/overwrite-random');
-const { getBrowserFrames, stringArrayFind } = require('./lib/utils');
+const { getBrowserFrames, stringArrayFind, getPageViewportSize, setPageViewportSize } = require('./lib/utils');
 
 module.exports = async function (config) {
   config = Object.assign({}, config || {});
@@ -150,13 +150,13 @@ module.exports = async function (config) {
     if (config.viewport || scaleArg) {
       config.viewport = Object.assign(
         {
-          width: page.viewport().width,
-          height: page.viewport().height,
+          width: getPageViewportSize(page).width,
+          height: getPageViewportSize(page).height,
           deviceScaleFactor: scaleArg ? Number(scaleArg.split('=')[1]) || 1 : 1
         },
         config.viewport
       );
-      await page.setViewport(config.viewport);
+      await setPageViewportSize(page, config.viewport);
     }
     await overwriteRandom(page, unrandom, log);
     await timeHandler.overwriteTime(page);
diff --git a/lib/capture-canvas.js b/lib/capture-canvas.js
index aa17a06..63fc40a 100644
--- a/lib/capture-canvas.js
+++ b/lib/capture-canvas.js
@@ -33,9 +33,9 @@
 const makeCanvasCapturer = require('./make-canvas-capturer');
 
 const canvasToBuffer = async function (page, canvasSelector, type, quality) {
-  var dataUrl = await page.evaluate((canvasSelector, type, quality) =>
+  var dataUrl = await page.evaluate(({ canvasSelector, type, quality }) =>
     document.querySelector(canvasSelector).toDataURL(type, quality)
-  , canvasSelector, type, quality);
+  , { canvasSelector, type, quality });
   var data = dataUrl.slice(dataUrl.indexOf(',') + 1);
   return new Buffer(data, 'base64');
 };
diff --git a/lib/capture-screenshot.js b/lib/capture-screenshot.js
index ea802c4..fb9a5c1 100644
--- a/lib/capture-screenshot.js
+++ b/lib/capture-screenshot.js
@@ -30,7 +30,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-const { getSelectorDimensions, makeFilePathConverter, makeFileDirectoryIfNeeded } = require('./utils.js');
+const { getSelectorDimensions, getPageViewportSize, makeFilePathConverter, makeFileDirectoryIfNeeded } = require('./utils.js');
 
 module.exports = function (config) {
   var page = config.page;
@@ -47,7 +47,7 @@ module.exports = function (config) {
           log('Warning: no element found for ' + config.selector);
         }
       }
-      var viewport = page.viewport();
+      var viewport = getPageViewportSize(page);
       var x = config.xOffset || config.left || 0;
       var y = config.yOffset || config.top || 0;
       var right = config.right || 0;
diff --git a/lib/immediate-canvas-handler.js b/lib/immediate-canvas-handler.js
index 6927f28..9fa5573 100644
--- a/lib/immediate-canvas-handler.js
+++ b/lib/immediate-canvas-handler.js
@@ -52,11 +52,11 @@ module.exports = function (config) {
   if (config.alwaysSaveCanvasData) {
     goToTime = async function (browserFrames, time) {
       // Goes to a certain time. Can't go backwards
-      return page.evaluate((ms, canvasSelector, type, quality) => {
-        window._timeweb_processUntilTime(ms);
+      return page.evaluate(({ ms, canvasSelector, type, quality }) => {
+        window.timeweb.processUntilTime(ms);
         var canvasElement = document.querySelector(canvasSelector);
         window._timesnap_canvasData = canvasElement.toDataURL(type, quality);
-      }, time, canvasSelector, canvasCaptureMode, quality);
+      }, { ms: time, canvasSelector, type: canvasCaptureMode, quality });
     };
   } else {
     goToTime = oldGoToTime;
@@ -64,14 +64,14 @@ module.exports = function (config) {
 
   const goToTimeAndAnimateForCapture = async function (browserFrames, time) {
     // Goes to a certain time. Can't go backwards
-    return page.evaluate((ms, canvasSelector, type, quality) => {
-      window._timeweb_processUntilTime(ms);
-      return window._timeweb_runFramePreparers(ms, function () {
-        window._timeweb_runAnimationFrames();
+    return page.evaluate(({ ms, canvasSelector, type, quality }) => {
+      window.timeweb.processUntilTime(ms);
+      return window.timeweb.runFramePreparers(ms, function () {
+        window.timeweb.runAnimationFrames();
         var canvasElement = document.querySelector(canvasSelector);
         window._timesnap_canvasData = canvasElement.toDataURL(type, quality);
       });
-    }, time, canvasSelector, canvasCaptureMode, quality);
+    }, { ms: time, canvasSelector, type: canvasCaptureMode, quality });
   };
 
   var goToTimeAndAnimate;
@@ -81,8 +81,8 @@ module.exports = function (config) {
     goToTimeAndAnimate = async function (browserFrames, time) {
       // Goes to a certain time. Can't go backwards
       return page.evaluate(function (ms) {
-        window._timeweb_processUntilTime(ms);
-        return window._timeweb_runFramePreparers(ms, window._timeweb_runAnimationFrames);
+        window.timeweb.processUntilTime(ms);
+        return window.timeweb.runFramePreparers(ms, window.timeweb.runAnimationFrames);
       }, time);
     };
   }
diff --git a/lib/overwrite-random.js b/lib/overwrite-random.js
index fafc0b3..ffefc0f 100644
--- a/lib/overwrite-random.js
+++ b/lib/overwrite-random.js
@@ -30,6 +30,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+const { evaluateOnNewDocument } = require('./utils.js');
+
 // unrandomizer seed constants
 // default seed values are only used if all of the seed values end up being 0
 const defaultSeed1 = 10;
@@ -61,7 +63,7 @@ const overwriteRandom = function (page, unrandom, log) {
 };
 
 const overwritePageRandom = function (page, seed1 = 0, seed2 = 0, seed3 = 0, seed4 = 0) {
-  return page.evaluateOnNewDocument(function (config) {
+  return evaluateOnNewDocument(page, function (config) {
     (function (exports) {
       let shift1 = 23;
       let shift2 = 17;
diff --git a/lib/overwrite-time.js b/lib/overwrite-time.js
index 69eb8cd..24cf0a8 100644
--- a/lib/overwrite-time.js
+++ b/lib/overwrite-time.js
@@ -31,20 +31,21 @@
  */
 const fs = require('fs');
 const path = require('path');
+const { evaluateOnNewDocument } = require('./utils.js');
 
 const timewebLib = fs.readFileSync(
   path.join(require.resolve('timeweb/dist/timeweb.js')),
   { encoding: 'utf8' }
 );
 const overwriteTime = async function (page) {
-  return page.evaluateOnNewDocument(timewebLib);
+  return evaluateOnNewDocument(page, timewebLib);
 };
 
 const goToTime = async function (browserFrames, time) {
   // Goes to a certain time. Can't go backwards
   return Promise.all(browserFrames.map(function (frame) {
     return frame.evaluate(function (ms) {
-      window._timeweb_processUntilTime(ms);
+      window.timeweb.processUntilTime(ms);
     }, time);
   }));
 };
@@ -53,8 +54,8 @@ const goToTimeAndAnimate = async function (browserFrames, time) {
   // Goes to a certain time. Can't go backwards
   return Promise.all(browserFrames.map(function (frame) {
     return frame.evaluate(function (ms) {
-      window._timeweb_processUntilTime(ms);
-      return window._timeweb_runFramePreparers(ms, window._timeweb_runAnimationFrames);
+      window.timeweb.processUntilTime(ms);
+      return window.timeweb.runFramePreparers(ms, window.timeweb.runAnimationFrames);
     }, time);
   }));
 };
diff --git a/lib/utils.js b/lib/utils.js
index b8e2c3d..5544cfe 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -41,6 +41,38 @@ const getBrowserFrames = function (frame) {
   return [frame].concat(...frame.childFrames().map(getBrowserFrames));
 };
 
+const evaluateOnNewDocument = function (page, fn, arg) {
+  if (page.evaluateOnNewDocument) {
+    if (arg !== undefined) {
+      page.evaluateOnNewDocument(fn, arg);
+    } else {
+      page.evaluateOnNewDocument(fn);
+    }
+  } else if (page.addInitScript) {
+    if (arg !== undefined) {
+      page.addInitScript(fn, arg);
+    } else {
+      page.addInitScript(fn);
+    }
+  }
+};
+
+const getPageViewportSize = function (page) {
+  if (page.viewport) {
+    return page.viewport();
+  } else if (page.viewportSize) {
+    return page.viewportSize();
+  }
+};
+
+const setPageViewportSize = async function (page, config) {
+  if (page.setViewport) {
+    return page.setViewport(config);
+  } else if (page.setViewportSize) {
+    return page.setViewportSize(config);
+  }
+};
+
 const getSelectorDimensions = async function (page, selector) {
   return page.evaluate(function (selector) {
     var el = document.querySelector(selector);
@@ -116,6 +148,9 @@ const makeFileDirectoryIfNeeded = function (filepath) {
 
 module.exports = {
   getBrowserFrames,
+  evaluateOnNewDocument,
+  getPageViewportSize,
+  setPageViewportSize,
   getSelectorDimensions,
   writeFile,
   stringArrayFind,
diff --git a/package-lock.json b/package-lock.json
index f8cc09a..91f9e4f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "timesnap-core",
-  "version": "0.3.1-prerelease",
+  "version": "0.3.1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -1025,9 +1025,9 @@
       "dev": true
     },
     "timeweb": {
-      "version": "0.1.1",
-      "resolved": "https://registry.npmjs.org/timeweb/-/timeweb-0.1.1.tgz",
-      "integrity": "sha512-GP4lwJNKeEvAP30MatdV2Rigi8eASIgzI3rBGyvObU1rg3K3AgfeJSNi5qbrTEUdQYRfknACjb7OYZm16fdkTQ=="
+      "version": "0.2.0",
+      "resolved": "https://registry.npmjs.org/timeweb/-/timeweb-0.2.0.tgz",
+      "integrity": "sha512-VKm6YWgQ0kKQVVsVVMZW3Fhx2ZraWk3QY9CLbPFdKkX5UpItt4KMcmZoZVzj8UVBph+3khLr0XMjlLFhB4c7FA=="
     },
     "tmp": {
       "version": "0.0.33",
diff --git a/package.json b/package.json
index c64a5ea..e7fa31b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "timesnap-core",
-  "version": "0.3.1-prerelease",
+  "version": "0.3.1",
   "description": "Take screenshots of web pages at smooth intervals",
   "repository": {
     "type": "git",
@@ -18,7 +18,7 @@
   },
   "license": "BSD-3-Clause",
   "dependencies": {
-    "timeweb": "^0.1.1",
+    "timeweb": "^0.2.0",
     "sprintf-js": "1.1.1"
   },
   "devDependencies": {