diff --git a/changelog.md b/changelog.md
index 9f0487e..023ecb7 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,6 +1,9 @@
 ## Changelog
 
-##### v.3.0.21 - 2016-05-19
+##### v.4.0.0 - 2017-07-12
+* Changed how Autosize determines the inital height. Fixes #336.
+
+##### v.3.0.21 - 2017-05-19
 * Fixed bug with overflow detection which degraded performance of textareas that exceed their max-width. Fixes #333.
 
 ##### v.3.0.20 - 2016-12-04
diff --git a/dist/autosize.js b/dist/autosize.js
index f844dfb..e0a21c7 100644
--- a/dist/autosize.js
+++ b/dist/autosize.js
@@ -1,5 +1,5 @@
 /*!
-	Autosize 3.0.21
+	Autosize 4.0.0
 	license: MIT
 	http://www.jacklmoore.com/autosize
 */
@@ -126,7 +126,7 @@
 			var overflows = getParentOverflows(ta);
 			var docTop = document.documentElement && document.documentElement.scrollTop; // Needed for Mobile IE (ticket #240)
 
-			ta.style.height = 'auto';
+			ta.style.height = '';
 
 			var endHeight = ta.scrollHeight + heightOffset;
 
diff --git a/dist/autosize.min.js b/dist/autosize.min.js
index 770cc25..2a162d3 100644
--- a/dist/autosize.min.js
+++ b/dist/autosize.min.js
@@ -1,6 +1,6 @@
 /*!
-	Autosize 3.0.21
+	Autosize 4.0.0
 	license: MIT
 	http://www.jacklmoore.com/autosize
 */
-!function(e,t){if("function"==typeof define&&define.amd)define(["exports","module"],t);else if("undefined"!=typeof exports&&"undefined"!=typeof module)t(exports,module);else{var n={exports:{}};t(n.exports,n),e.autosize=n.exports}}(this,function(e,t){"use strict";function n(e){function t(){var t=window.getComputedStyle(e,null);"vertical"===t.resize?e.style.resize="none":"both"===t.resize&&(e.style.resize="horizontal"),s="content-box"===t.boxSizing?-(parseFloat(t.paddingTop)+parseFloat(t.paddingBottom)):parseFloat(t.borderTopWidth)+parseFloat(t.borderBottomWidth),isNaN(s)&&(s=0),l()}function n(t){var n=e.style.width;e.style.width="0px",e.offsetWidth,e.style.width=n,e.style.overflowY=t}function o(e){for(var t=[];e&&e.parentNode&&e.parentNode instanceof Element;)e.parentNode.scrollTop&&t.push({node:e.parentNode,scrollTop:e.parentNode.scrollTop}),e=e.parentNode;return t}function r(){var t=e.style.height,n=o(e),r=document.documentElement&&document.documentElement.scrollTop;e.style.height="auto";var i=e.scrollHeight+s;return 0===e.scrollHeight?void(e.style.height=t):(e.style.height=i+"px",u=e.clientWidth,n.forEach(function(e){e.node.scrollTop=e.scrollTop}),void(r&&(document.documentElement.scrollTop=r)))}function l(){r();var t=Math.round(parseFloat(e.style.height)),o=window.getComputedStyle(e,null),i="content-box"===o.boxSizing?Math.round(parseFloat(o.height)):e.offsetHeight;if(i!==t?"hidden"===o.overflowY&&(n("scroll"),r(),i="content-box"===o.boxSizing?Math.round(parseFloat(window.getComputedStyle(e,null).height)):e.offsetHeight):"hidden"!==o.overflowY&&(n("hidden"),r(),i="content-box"===o.boxSizing?Math.round(parseFloat(window.getComputedStyle(e,null).height)):e.offsetHeight),a!==i){a=i;var l=d("autosize:resized");try{e.dispatchEvent(l)}catch(e){}}}if(e&&e.nodeName&&"TEXTAREA"===e.nodeName&&!i.has(e)){var s=null,u=e.clientWidth,a=null,c=function(){e.clientWidth!==u&&l()},p=function(t){window.removeEventListener("resize",c,!1),e.removeEventListener("input",l,!1),e.removeEventListener("keyup",l,!1),e.removeEventListener("autosize:destroy",p,!1),e.removeEventListener("autosize:update",l,!1),Object.keys(t).forEach(function(n){e.style[n]=t[n]}),i.delete(e)}.bind(e,{height:e.style.height,resize:e.style.resize,overflowY:e.style.overflowY,overflowX:e.style.overflowX,wordWrap:e.style.wordWrap});e.addEventListener("autosize:destroy",p,!1),"onpropertychange"in e&&"oninput"in e&&e.addEventListener("keyup",l,!1),window.addEventListener("resize",c,!1),e.addEventListener("input",l,!1),e.addEventListener("autosize:update",l,!1),e.style.overflowX="hidden",e.style.wordWrap="break-word",i.set(e,{destroy:p,update:l}),t()}}function o(e){var t=i.get(e);t&&t.destroy()}function r(e){var t=i.get(e);t&&t.update()}var i="function"==typeof Map?new Map:function(){var e=[],t=[];return{has:function(t){return e.indexOf(t)>-1},get:function(n){return t[e.indexOf(n)]},set:function(n,o){e.indexOf(n)===-1&&(e.push(n),t.push(o))},delete:function(n){var o=e.indexOf(n);o>-1&&(e.splice(o,1),t.splice(o,1))}}}(),d=function(e){return new Event(e,{bubbles:!0})};try{new Event("test")}catch(e){d=function(e){var t=document.createEvent("Event");return t.initEvent(e,!0,!1),t}}var l=null;"undefined"==typeof window||"function"!=typeof window.getComputedStyle?(l=function(e){return e},l.destroy=function(e){return e},l.update=function(e){return e}):(l=function(e,t){return e&&Array.prototype.forEach.call(e.length?e:[e],function(e){return n(e,t)}),e},l.destroy=function(e){return e&&Array.prototype.forEach.call(e.length?e:[e],o),e},l.update=function(e){return e&&Array.prototype.forEach.call(e.length?e:[e],r),e}),t.exports=l});
\ No newline at end of file
+!function(e,t){if("function"==typeof define&&define.amd)define(["exports","module"],t);else if("undefined"!=typeof exports&&"undefined"!=typeof module)t(exports,module);else{var n={exports:{}};t(n.exports,n),e.autosize=n.exports}}(this,function(e,t){"use strict";function n(e){function t(){var t=window.getComputedStyle(e,null);"vertical"===t.resize?e.style.resize="none":"both"===t.resize&&(e.style.resize="horizontal"),s="content-box"===t.boxSizing?-(parseFloat(t.paddingTop)+parseFloat(t.paddingBottom)):parseFloat(t.borderTopWidth)+parseFloat(t.borderBottomWidth),isNaN(s)&&(s=0),l()}function n(t){var n=e.style.width;e.style.width="0px",e.offsetWidth,e.style.width=n,e.style.overflowY=t}function o(e){for(var t=[];e&&e.parentNode&&e.parentNode instanceof Element;)e.parentNode.scrollTop&&t.push({node:e.parentNode,scrollTop:e.parentNode.scrollTop}),e=e.parentNode;return t}function r(){var t=e.style.height,n=o(e),r=document.documentElement&&document.documentElement.scrollTop;e.style.height="";var i=e.scrollHeight+s;return 0===e.scrollHeight?void(e.style.height=t):(e.style.height=i+"px",u=e.clientWidth,n.forEach(function(e){e.node.scrollTop=e.scrollTop}),void(r&&(document.documentElement.scrollTop=r)))}function l(){r();var t=Math.round(parseFloat(e.style.height)),o=window.getComputedStyle(e,null),i="content-box"===o.boxSizing?Math.round(parseFloat(o.height)):e.offsetHeight;if(i!==t?"hidden"===o.overflowY&&(n("scroll"),r(),i="content-box"===o.boxSizing?Math.round(parseFloat(window.getComputedStyle(e,null).height)):e.offsetHeight):"hidden"!==o.overflowY&&(n("hidden"),r(),i="content-box"===o.boxSizing?Math.round(parseFloat(window.getComputedStyle(e,null).height)):e.offsetHeight),a!==i){a=i;var l=d("autosize:resized");try{e.dispatchEvent(l)}catch(e){}}}if(e&&e.nodeName&&"TEXTAREA"===e.nodeName&&!i.has(e)){var s=null,u=e.clientWidth,a=null,c=function(){e.clientWidth!==u&&l()},p=function(t){window.removeEventListener("resize",c,!1),e.removeEventListener("input",l,!1),e.removeEventListener("keyup",l,!1),e.removeEventListener("autosize:destroy",p,!1),e.removeEventListener("autosize:update",l,!1),Object.keys(t).forEach(function(n){e.style[n]=t[n]}),i.delete(e)}.bind(e,{height:e.style.height,resize:e.style.resize,overflowY:e.style.overflowY,overflowX:e.style.overflowX,wordWrap:e.style.wordWrap});e.addEventListener("autosize:destroy",p,!1),"onpropertychange"in e&&"oninput"in e&&e.addEventListener("keyup",l,!1),window.addEventListener("resize",c,!1),e.addEventListener("input",l,!1),e.addEventListener("autosize:update",l,!1),e.style.overflowX="hidden",e.style.wordWrap="break-word",i.set(e,{destroy:p,update:l}),t()}}function o(e){var t=i.get(e);t&&t.destroy()}function r(e){var t=i.get(e);t&&t.update()}var i="function"==typeof Map?new Map:function(){var e=[],t=[];return{has:function(t){return e.indexOf(t)>-1},get:function(n){return t[e.indexOf(n)]},set:function(n,o){e.indexOf(n)===-1&&(e.push(n),t.push(o))},delete:function(n){var o=e.indexOf(n);o>-1&&(e.splice(o,1),t.splice(o,1))}}}(),d=function(e){return new Event(e,{bubbles:!0})};try{new Event("test")}catch(e){d=function(e){var t=document.createEvent("Event");return t.initEvent(e,!0,!1),t}}var l=null;"undefined"==typeof window||"function"!=typeof window.getComputedStyle?(l=function(e){return e},l.destroy=function(e){return e},l.update=function(e){return e}):(l=function(e,t){return e&&Array.prototype.forEach.call(e.length?e:[e],function(e){return n(e,t)}),e},l.destroy=function(e){return e&&Array.prototype.forEach.call(e.length?e:[e],o),e},l.update=function(e){return e&&Array.prototype.forEach.call(e.length?e:[e],r),e}),t.exports=l});
\ No newline at end of file
diff --git a/package.json b/package.json
index 88d9d51..6760d73 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "autosize",
   "description": "Autosize is a small, stand-alone script to automatically adjust textarea height to fit text.",
-  "version": "3.0.21",
+  "version": "4.0.0",
   "keywords": [
     "textarea",
     "form",
diff --git a/src/autosize.js b/src/autosize.js
index dd891c3..5b34551 100644
--- a/src/autosize.js
+++ b/src/autosize.js
@@ -104,7 +104,7 @@ function assign(ta) {
 		const overflows = getParentOverflows(ta);
 		const docTop = document.documentElement && document.documentElement.scrollTop; // Needed for Mobile IE (ticket #240)
 
-		ta.style.height = 'auto';
+		ta.style.height = '';
 
 		let endHeight = ta.scrollHeight+heightOffset;