diff --git a/.nvmrc b/.nvmrc
index ec635144..f599e28b 100644
--- a/.nvmrc
+++ b/.nvmrc
@@ -1 +1 @@
-9
+10
diff --git a/dist/jquery.stickybits.min.js b/dist/jquery.stickybits.min.js
index 93b3c530..ada64c08 100644
--- a/dist/jquery.stickybits.min.js
+++ b/dist/jquery.stickybits.min.js
@@ -1,8 +1,8 @@
 /**
   stickybits - Stickybits is a lightweight alternative to `position: sticky` polyfills
-  @version v3.3.1
+  @version v3.3.2
   @link https://github.com/dollarshaveclub/stickybits#readme
   @author Jeff Wainwright <yowainwright@gmail.com> (https://jeffry.in)
   @license MIT
 **/
-!function(t,s){"object"==typeof exports&&"undefined"!=typeof module?s():"function"==typeof define&&define.amd?define(s):s()}(0,function(){"use strict";var t=function(){function t(t,s){var e=void 0!==s?s:{};this.version="3.3.1",this.userAgent=window.navigator.userAgent||"no `userAgent` provided by the browser",this.props={customStickyChangeNumber:e.customStickyChangeNumber||null,noStyles:e.noStyles||!1,stickyBitStickyOffset:e.stickyBitStickyOffset||0,parentClass:e.parentClass||"js-stickybit-parent",scrollEl:document.querySelector(e.scrollEl)||window,stickyClass:e.stickyClass||"js-is-sticky",stuckClass:e.stuckClass||"js-is-stuck",stickyChangeClass:e.stickyChangeClass||"js-is-sticky--change",useStickyClasses:e.useStickyClasses||!1,verticalPosition:e.verticalPosition||"top"};var i=this.props;i.positionVal=this.definePosition()||"fixed";var n=i.verticalPosition,o=i.noStyles,a=i.positionVal;this.els="string"==typeof t?document.querySelectorAll(t):t,"length"in this.els||(this.els=[this.els]),this.instances=[];for(var r=0;r<this.els.length;r+=1){var c=this.els[r],l=c.style;if(l[n]="top"!==n||o?"":i.stickyBitStickyOffset+"px",l.position="fixed"!==a?a:"","fixed"===a||i.useStickyClasses){var f=this.addInstance(c,i);this.instances.push(f)}}return this}var s=t.prototype;return s.definePosition=function(){for(var t=["","-o-","-webkit-","-moz-","-ms-"],s=document.head.style,e=0;e<t.length;e+=1)s.position=t[e]+"sticky";var i=s.position?s.position:"fixed";return s.position="",i},s.addInstance=function(t,s){var e=this,i={el:t,parent:t.parentNode,props:s};this.isWin=this.props.scrollEl===window;var n=this.isWin?window:this.getClosestParent(i.el,i.props.scrollEl);return this.computeScrollOffsets(i),i.parent.className+=" "+s.parentClass,i.state="default",i.stateContainer=function(){return e.manageState(i)},n.addEventListener("scroll",i.stateContainer),i},s.getClosestParent=function(t,s){var e=s,i=t;if(i.parentElement===e)return e;for(;i.parentElement!==e;)i=i.parentElement;return e},s.computeScrollOffsets=function(t){var s=t,e=s.props,i=s.el,n=s.parent,o=!this.isWin&&"fixed"===e.positionVal,a="bottom"!==e.verticalPosition,r=o?e.scrollEl.getBoundingClientRect().top:0,c=o?n.getBoundingClientRect().top-r:n.getBoundingClientRect().top,l=null!==e.customStickyChangeNumber?e.customStickyChangeNumber:i.offsetHeight;return s.offset=r+e.stickyBitStickyOffset,s.stickyStart=a?c-s.offset:0,s.stickyChange=s.stickyStart+l,s.stickyStop=a?c+n.offsetHeight-(s.el.offsetHeight+s.offset):c+n.offsetHeight,s},s.toggleClasses=function(t,s,e){var i=t,n=i.className.split(" ");e&&-1===n.indexOf(e)&&n.push(e);var o=n.indexOf(s);-1!==o&&n.splice(o,1),i.className=n.join(" ")},s.manageState=function(t){var s=t,e=s.el,i=s.props,n=s.state,o=s.stickyStart,a=s.stickyChange,r=s.stickyStop,c=e.style,l=i.noStyles,f=i.positionVal,u=i.scrollEl,p=i.stickyClass,h=i.stickyChangeClass,y=i.stuckClass,d=i.verticalPosition,k=function(t){t()},m=this.isWin&&(window.requestAnimationFrame||window.mozRequestAnimationFrame||window.webkitRequestAnimationFrame||window.msRequestAnimationFrame)||k,g=this.toggleClasses,v=this.isWin?window.scrollY||window.pageYOffset:u.scrollTop,C=v<=o&&"sticky"===n,w=v>=r&&"sticky"===n;v>o&&v<r&&("default"===n||"stuck"===n)?(s.state="sticky",m(function(){g(e,y,p),c.position=f,l||(c.bottom="",c[d]=i.stickyBitStickyOffset+"px")})):C?(s.state="default",m(function(){g(e,p),"fixed"===f&&(c.position="")})):w&&(s.state="stuck",m(function(){g(e,p,y),"fixed"!==f||l||(c.top="",c.bottom="0",c.position="absolute")}));var S=v>=a&&v<=r;return v<a||v>r?m(function(){g(e,h)}):S&&m(function(){g(e,"stub",h)}),s},s.update=function(){for(var t=0;t<this.instances.length;t+=1){var s=this.instances[t];this.computeScrollOffsets(s)}return this},s.removeInstance=function(t){var s=t.el,e=t.props,i=this.toggleClasses;s.style.position="",s.style[e.verticalPosition]="",i(s,e.stickyClass),i(s,e.stuckClass),i(s.parentNode,e.parentClass)},s.cleanup=function(){for(var t=0;t<this.instances.length;t+=1){var s=this.instances[t];s.props.scrollEl.removeEventListener("scroll",s.stateContainer),this.removeInstance(s)}this.manageState=!1,this.instances=[]},t}();if("undefined"!=typeof window){var s=window.$||window.jQuery||window.Zepto;s&&(s.fn.stickybits=function(s){new t(this,s)})}});
+!function(t,s){"object"==typeof exports&&"undefined"!=typeof module?s():"function"==typeof define&&define.amd?define(s):s()}(0,function(){"use strict";var t=function(){function t(t,s){var e=void 0!==s?s:{};this.version="3.3.2",this.userAgent=window.navigator.userAgent||"no `userAgent` provided by the browser",this.props={customStickyChangeNumber:e.customStickyChangeNumber||null,noStyles:e.noStyles||!1,stickyBitStickyOffset:e.stickyBitStickyOffset||0,parentClass:e.parentClass||"js-stickybit-parent",scrollEl:document.querySelector(e.scrollEl)||window,stickyClass:e.stickyClass||"js-is-sticky",stuckClass:e.stuckClass||"js-is-stuck",stickyChangeClass:e.stickyChangeClass||"js-is-sticky--change",useStickyClasses:e.useStickyClasses||!1,verticalPosition:e.verticalPosition||"top"};var i=this.props;i.positionVal=this.definePosition()||"fixed";var n=i.verticalPosition,o=i.noStyles,a=i.positionVal;this.els="string"==typeof t?document.querySelectorAll(t):t,"length"in this.els||(this.els=[this.els]),this.instances=[];for(var r=0;r<this.els.length;r+=1){var c=this.els[r],l=c.style;if(l[n]="top"!==n||o?"":i.stickyBitStickyOffset+"px",l.position="fixed"!==a?a:"","fixed"===a||i.useStickyClasses){var f=this.addInstance(c,i);this.instances.push(f)}}return this}var s=t.prototype;return s.definePosition=function(){for(var t=["","-o-","-webkit-","-moz-","-ms-"],s=document.head.style,e=0;e<t.length;e+=1)s.position=t[e]+"sticky";var i=s.position?s.position:"fixed";return s.position="",i},s.addInstance=function(t,s){var e=this,i={el:t,parent:t.parentNode,props:s};this.isWin=this.props.scrollEl===window;var n=this.isWin?window:this.getClosestParent(i.el,i.props.scrollEl);return this.computeScrollOffsets(i),i.parent.className+=" "+s.parentClass,i.state="default",i.stateContainer=function(){return e.manageState(i)},n.addEventListener("scroll",i.stateContainer),i},s.getClosestParent=function(t,s){var e=s,i=t;if(i.parentElement===e)return e;for(;i.parentElement!==e;)i=i.parentElement;return e},s.getOffsetTop=function(t){var s=0;do{s=t.offsetTop+s}while(t=t.offsetParent);return s},s.computeScrollOffsets=function(t){var s=t,e=s.props,i=s.el,n=s.parent,o=!this.isWin&&"fixed"===e.positionVal,a="bottom"!==e.verticalPosition,r=o?this.getOffsetTop(e.scrollEl):0,c=o?this.getOffsetTop(n)-r:this.getOffsetTop(n),l=null!==e.customStickyChangeNumber?e.customStickyChangeNumber:i.offsetHeight;return s.offset=r+e.stickyBitStickyOffset,s.stickyStart=a?c-s.offset:0,s.stickyChange=s.stickyStart+l,s.stickyStop=a?c+n.offsetHeight-(s.el.offsetHeight+s.offset):c+n.offsetHeight,s},s.toggleClasses=function(t,s,e){var i=t,n=i.className.split(" ");e&&-1===n.indexOf(e)&&n.push(e);var o=n.indexOf(s);-1!==o&&n.splice(o,1),i.className=n.join(" ")},s.manageState=function(t){var s=t,e=s.el,i=s.props,n=s.state,o=s.stickyStart,a=s.stickyChange,r=s.stickyStop,c=e.style,l=i.noStyles,f=i.positionVal,u=i.scrollEl,p=i.stickyClass,h=i.stickyChangeClass,y=i.stuckClass,d=i.verticalPosition,k=function(t){t()},m=this.isWin&&(window.requestAnimationFrame||window.mozRequestAnimationFrame||window.webkitRequestAnimationFrame||window.msRequestAnimationFrame)||k,g=this.toggleClasses,v=this.isWin?window.scrollY||window.pageYOffset:u.scrollTop,C=v<=o&&"sticky"===n,w=v>=r&&"sticky"===n;v>o&&v<r&&("default"===n||"stuck"===n)?(s.state="sticky",m(function(){g(e,y,p),c.position=f,l||(c.bottom="",c[d]=i.stickyBitStickyOffset+"px")})):C?(s.state="default",m(function(){g(e,p),"fixed"===f&&(c.position="")})):w&&(s.state="stuck",m(function(){g(e,p,y),"fixed"!==f||l||(c.top="",c.bottom="0",c.position="absolute")}));var S=v>=a&&v<=r;return v<a||v>r?m(function(){g(e,h)}):S&&m(function(){g(e,"stub",h)}),s},s.update=function(){for(var t=0;t<this.instances.length;t+=1){var s=this.instances[t];this.computeScrollOffsets(s)}return this},s.removeInstance=function(t){var s=t.el,e=t.props,i=this.toggleClasses;s.style.position="",s.style[e.verticalPosition]="",i(s,e.stickyClass),i(s,e.stuckClass),i(s.parentNode,e.parentClass)},s.cleanup=function(){for(var t=0;t<this.instances.length;t+=1){var s=this.instances[t];s.props.scrollEl.removeEventListener("scroll",s.stateContainer),this.removeInstance(s)}this.manageState=!1,this.instances=[]},t}();if("undefined"!=typeof window){var s=window.$||window.jQuery||window.Zepto;s&&(s.fn.stickybits=function(s){new t(this,s)})}});
diff --git a/dist/stickybits.es.js b/dist/stickybits.es.js
index eb040fd4..065b0ead 100644
--- a/dist/stickybits.es.js
+++ b/dist/stickybits.es.js
@@ -1,6 +1,6 @@
 /**
   stickybits - Stickybits is a lightweight alternative to `position: sticky` polyfills
-  @version v3.3.1
+  @version v3.3.2
   @link https://github.com/dollarshaveclub/stickybits#readme
   @author Jeff Wainwright <yowainwright@gmail.com> (https://jeffry.in)
   @license MIT
@@ -50,6 +50,7 @@
   - .definePosition = defines sticky or fixed
   - .addInstance = an array of objects for each Stickybits Target
   - .getClosestParent = gets the parent for non-window scroll
+  - .getOffsetTop = gets the element offsetTop from the top level of the DOM
   - .computeScrollOffsets = computes scroll position
   - .toggleClasses = older browser toggler
   - .manageState = manages sticky state
@@ -62,7 +63,7 @@ var Stickybits =
 function () {
   function Stickybits(target, obj) {
     var o = typeof obj !== 'undefined' ? obj : {};
-    this.version = '3.3.1';
+    this.version = '3.3.2';
     this.userAgent = window.navigator.userAgent || 'no `userAgent` provided by the browser';
     this.props = {
       customStickyChangeNumber: o.customStickyChangeNumber || null,
@@ -202,6 +203,24 @@ function () {
 
     return p;
   };
+  /*
+    --------
+    getOffsetTop
+    --------
+    - a helper function that gets the offsetTop of the element
+    - from the top level of the DOM
+  */
+
+
+  _proto.getOffsetTop = function getOffsetTop(el) {
+    var offsetTop = 0;
+
+    do {
+      offsetTop = el.offsetTop + offsetTop;
+    } while (el = el.offsetParent);
+
+    return offsetTop;
+  };
   /*
     computeScrollOffsets 📊
     ---
@@ -220,8 +239,8 @@ function () {
     var parent = it.parent;
     var isCustom = !this.isWin && p.positionVal === 'fixed';
     var isBottom = p.verticalPosition !== 'bottom';
-    var scrollElOffset = isCustom ? p.scrollEl.getBoundingClientRect().top : 0;
-    var stickyStart = isCustom ? parent.getBoundingClientRect().top - scrollElOffset : parent.getBoundingClientRect().top;
+    var scrollElOffset = isCustom ? this.getOffsetTop(p.scrollEl) : 0;
+    var stickyStart = isCustom ? this.getOffsetTop(parent) - scrollElOffset : this.getOffsetTop(parent);
     var stickyChangeOffset = p.customStickyChangeNumber !== null ? p.customStickyChangeNumber : el.offsetHeight;
     it.offset = scrollElOffset + p.stickyBitStickyOffset;
     it.stickyStart = isBottom ? stickyStart - it.offset : 0;
diff --git a/dist/stickybits.js b/dist/stickybits.js
index 734c9cba..1398a96b 100644
--- a/dist/stickybits.js
+++ b/dist/stickybits.js
@@ -1,6 +1,6 @@
 /**
   stickybits - Stickybits is a lightweight alternative to `position: sticky` polyfills
-  @version v3.3.1
+  @version v3.3.2
   @link https://github.com/dollarshaveclub/stickybits#readme
   @author Jeff Wainwright <yowainwright@gmail.com> (https://jeffry.in)
   @license MIT
@@ -56,6 +56,7 @@
     - .definePosition = defines sticky or fixed
     - .addInstance = an array of objects for each Stickybits Target
     - .getClosestParent = gets the parent for non-window scroll
+    - .getOffsetTop = gets the element offsetTop from the top level of the DOM
     - .computeScrollOffsets = computes scroll position
     - .toggleClasses = older browser toggler
     - .manageState = manages sticky state
@@ -68,7 +69,7 @@
   function () {
     function Stickybits(target, obj) {
       var o = typeof obj !== 'undefined' ? obj : {};
-      this.version = '3.3.1';
+      this.version = '3.3.2';
       this.userAgent = window.navigator.userAgent || 'no `userAgent` provided by the browser';
       this.props = {
         customStickyChangeNumber: o.customStickyChangeNumber || null,
@@ -208,6 +209,24 @@
 
       return p;
     };
+    /*
+      --------
+      getOffsetTop
+      --------
+      - a helper function that gets the offsetTop of the element
+      - from the top level of the DOM
+    */
+
+
+    _proto.getOffsetTop = function getOffsetTop(el) {
+      var offsetTop = 0;
+
+      do {
+        offsetTop = el.offsetTop + offsetTop;
+      } while (el = el.offsetParent);
+
+      return offsetTop;
+    };
     /*
       computeScrollOffsets 📊
       ---
@@ -226,8 +245,8 @@
       var parent = it.parent;
       var isCustom = !this.isWin && p.positionVal === 'fixed';
       var isBottom = p.verticalPosition !== 'bottom';
-      var scrollElOffset = isCustom ? p.scrollEl.getBoundingClientRect().top : 0;
-      var stickyStart = isCustom ? parent.getBoundingClientRect().top - scrollElOffset : parent.getBoundingClientRect().top;
+      var scrollElOffset = isCustom ? this.getOffsetTop(p.scrollEl) : 0;
+      var stickyStart = isCustom ? this.getOffsetTop(parent) - scrollElOffset : this.getOffsetTop(parent);
       var stickyChangeOffset = p.customStickyChangeNumber !== null ? p.customStickyChangeNumber : el.offsetHeight;
       it.offset = scrollElOffset + p.stickyBitStickyOffset;
       it.stickyStart = isBottom ? stickyStart - it.offset : 0;
diff --git a/dist/stickybits.min.js b/dist/stickybits.min.js
index 3a2322d3..637f7991 100644
--- a/dist/stickybits.min.js
+++ b/dist/stickybits.min.js
@@ -1,8 +1,8 @@
 /**
   stickybits - Stickybits is a lightweight alternative to `position: sticky` polyfills
-  @version v3.3.1
+  @version v3.3.2
   @link https://github.com/dollarshaveclub/stickybits#readme
   @author Jeff Wainwright <yowainwright@gmail.com> (https://jeffry.in)
   @license MIT
 **/
-!function(t,s){"object"==typeof exports&&"undefined"!=typeof module?module.exports=s():"function"==typeof define&&define.amd?define(s):t.stickybits=s()}(this,function(){"use strict";var t=function(){function t(t,s){var e=void 0!==s?s:{};this.version="3.3.1",this.userAgent=window.navigator.userAgent||"no `userAgent` provided by the browser",this.props={customStickyChangeNumber:e.customStickyChangeNumber||null,noStyles:e.noStyles||!1,stickyBitStickyOffset:e.stickyBitStickyOffset||0,parentClass:e.parentClass||"js-stickybit-parent",scrollEl:document.querySelector(e.scrollEl)||window,stickyClass:e.stickyClass||"js-is-sticky",stuckClass:e.stuckClass||"js-is-stuck",stickyChangeClass:e.stickyChangeClass||"js-is-sticky--change",useStickyClasses:e.useStickyClasses||!1,verticalPosition:e.verticalPosition||"top"};var i=this.props;i.positionVal=this.definePosition()||"fixed";var n=i.verticalPosition,o=i.noStyles,a=i.positionVal;this.els="string"==typeof t?document.querySelectorAll(t):t,"length"in this.els||(this.els=[this.els]),this.instances=[];for(var r=0;r<this.els.length;r+=1){var l=this.els[r],c=l.style;if(c[n]="top"!==n||o?"":i.stickyBitStickyOffset+"px",c.position="fixed"!==a?a:"","fixed"===a||i.useStickyClasses){var u=this.addInstance(l,i);this.instances.push(u)}}return this}var s=t.prototype;return s.definePosition=function(){for(var t=["","-o-","-webkit-","-moz-","-ms-"],s=document.head.style,e=0;e<t.length;e+=1)s.position=t[e]+"sticky";var i=s.position?s.position:"fixed";return s.position="",i},s.addInstance=function(t,s){var e=this,i={el:t,parent:t.parentNode,props:s};this.isWin=this.props.scrollEl===window;var n=this.isWin?window:this.getClosestParent(i.el,i.props.scrollEl);return this.computeScrollOffsets(i),i.parent.className+=" "+s.parentClass,i.state="default",i.stateContainer=function(){return e.manageState(i)},n.addEventListener("scroll",i.stateContainer),i},s.getClosestParent=function(t,s){var e=s,i=t;if(i.parentElement===e)return e;for(;i.parentElement!==e;)i=i.parentElement;return e},s.computeScrollOffsets=function(t){var s=t,e=s.props,i=s.el,n=s.parent,o=!this.isWin&&"fixed"===e.positionVal,a="bottom"!==e.verticalPosition,r=o?e.scrollEl.getBoundingClientRect().top:0,l=o?n.getBoundingClientRect().top-r:n.getBoundingClientRect().top,c=null!==e.customStickyChangeNumber?e.customStickyChangeNumber:i.offsetHeight;return s.offset=r+e.stickyBitStickyOffset,s.stickyStart=a?l-s.offset:0,s.stickyChange=s.stickyStart+c,s.stickyStop=a?l+n.offsetHeight-(s.el.offsetHeight+s.offset):l+n.offsetHeight,s},s.toggleClasses=function(t,s,e){var i=t,n=i.className.split(" ");e&&-1===n.indexOf(e)&&n.push(e);var o=n.indexOf(s);-1!==o&&n.splice(o,1),i.className=n.join(" ")},s.manageState=function(t){var s=t,e=s.el,i=s.props,n=s.state,o=s.stickyStart,a=s.stickyChange,r=s.stickyStop,l=e.style,c=i.noStyles,u=i.positionVal,f=i.scrollEl,p=i.stickyClass,h=i.stickyChangeClass,y=i.stuckClass,d=i.verticalPosition,k=function(t){t()},m=this.isWin&&(window.requestAnimationFrame||window.mozRequestAnimationFrame||window.webkitRequestAnimationFrame||window.msRequestAnimationFrame)||k,g=this.toggleClasses,v=this.isWin?window.scrollY||window.pageYOffset:f.scrollTop,C=v<=o&&"sticky"===n,S=v>=r&&"sticky"===n;v>o&&v<r&&("default"===n||"stuck"===n)?(s.state="sticky",m(function(){g(e,y,p),l.position=u,c||(l.bottom="",l[d]=i.stickyBitStickyOffset+"px")})):C?(s.state="default",m(function(){g(e,p),"fixed"===u&&(l.position="")})):S&&(s.state="stuck",m(function(){g(e,p,y),"fixed"!==u||c||(l.top="",l.bottom="0",l.position="absolute")}));var w=v>=a&&v<=r;return v<a||v>r?m(function(){g(e,h)}):w&&m(function(){g(e,"stub",h)}),s},s.update=function(){for(var t=0;t<this.instances.length;t+=1){var s=this.instances[t];this.computeScrollOffsets(s)}return this},s.removeInstance=function(t){var s=t.el,e=t.props,i=this.toggleClasses;s.style.position="",s.style[e.verticalPosition]="",i(s,e.stickyClass),i(s,e.stuckClass),i(s.parentNode,e.parentClass)},s.cleanup=function(){for(var t=0;t<this.instances.length;t+=1){var s=this.instances[t];s.props.scrollEl.removeEventListener("scroll",s.stateContainer),this.removeInstance(s)}this.manageState=!1,this.instances=[]},t}();return function(s,e){return new t(s,e)}});
+!function(t,s){"object"==typeof exports&&"undefined"!=typeof module?module.exports=s():"function"==typeof define&&define.amd?define(s):t.stickybits=s()}(this,function(){"use strict";var t=function(){function t(t,s){var e=void 0!==s?s:{};this.version="3.3.2",this.userAgent=window.navigator.userAgent||"no `userAgent` provided by the browser",this.props={customStickyChangeNumber:e.customStickyChangeNumber||null,noStyles:e.noStyles||!1,stickyBitStickyOffset:e.stickyBitStickyOffset||0,parentClass:e.parentClass||"js-stickybit-parent",scrollEl:document.querySelector(e.scrollEl)||window,stickyClass:e.stickyClass||"js-is-sticky",stuckClass:e.stuckClass||"js-is-stuck",stickyChangeClass:e.stickyChangeClass||"js-is-sticky--change",useStickyClasses:e.useStickyClasses||!1,verticalPosition:e.verticalPosition||"top"};var i=this.props;i.positionVal=this.definePosition()||"fixed";var n=i.verticalPosition,o=i.noStyles,a=i.positionVal;this.els="string"==typeof t?document.querySelectorAll(t):t,"length"in this.els||(this.els=[this.els]),this.instances=[];for(var r=0;r<this.els.length;r+=1){var l=this.els[r],c=l.style;if(c[n]="top"!==n||o?"":i.stickyBitStickyOffset+"px",c.position="fixed"!==a?a:"","fixed"===a||i.useStickyClasses){var f=this.addInstance(l,i);this.instances.push(f)}}return this}var s=t.prototype;return s.definePosition=function(){for(var t=["","-o-","-webkit-","-moz-","-ms-"],s=document.head.style,e=0;e<t.length;e+=1)s.position=t[e]+"sticky";var i=s.position?s.position:"fixed";return s.position="",i},s.addInstance=function(t,s){var e=this,i={el:t,parent:t.parentNode,props:s};this.isWin=this.props.scrollEl===window;var n=this.isWin?window:this.getClosestParent(i.el,i.props.scrollEl);return this.computeScrollOffsets(i),i.parent.className+=" "+s.parentClass,i.state="default",i.stateContainer=function(){return e.manageState(i)},n.addEventListener("scroll",i.stateContainer),i},s.getClosestParent=function(t,s){var e=s,i=t;if(i.parentElement===e)return e;for(;i.parentElement!==e;)i=i.parentElement;return e},s.getOffsetTop=function(t){var s=0;do{s=t.offsetTop+s}while(t=t.offsetParent);return s},s.computeScrollOffsets=function(t){var s=t,e=s.props,i=s.el,n=s.parent,o=!this.isWin&&"fixed"===e.positionVal,a="bottom"!==e.verticalPosition,r=o?this.getOffsetTop(e.scrollEl):0,l=o?this.getOffsetTop(n)-r:this.getOffsetTop(n),c=null!==e.customStickyChangeNumber?e.customStickyChangeNumber:i.offsetHeight;return s.offset=r+e.stickyBitStickyOffset,s.stickyStart=a?l-s.offset:0,s.stickyChange=s.stickyStart+c,s.stickyStop=a?l+n.offsetHeight-(s.el.offsetHeight+s.offset):l+n.offsetHeight,s},s.toggleClasses=function(t,s,e){var i=t,n=i.className.split(" ");e&&-1===n.indexOf(e)&&n.push(e);var o=n.indexOf(s);-1!==o&&n.splice(o,1),i.className=n.join(" ")},s.manageState=function(t){var s=t,e=s.el,i=s.props,n=s.state,o=s.stickyStart,a=s.stickyChange,r=s.stickyStop,l=e.style,c=i.noStyles,f=i.positionVal,u=i.scrollEl,p=i.stickyClass,h=i.stickyChangeClass,y=i.stuckClass,d=i.verticalPosition,k=function(t){t()},m=this.isWin&&(window.requestAnimationFrame||window.mozRequestAnimationFrame||window.webkitRequestAnimationFrame||window.msRequestAnimationFrame)||k,g=this.toggleClasses,v=this.isWin?window.scrollY||window.pageYOffset:u.scrollTop,C=v<=o&&"sticky"===n,S=v>=r&&"sticky"===n;v>o&&v<r&&("default"===n||"stuck"===n)?(s.state="sticky",m(function(){g(e,y,p),l.position=f,c||(l.bottom="",l[d]=i.stickyBitStickyOffset+"px")})):C?(s.state="default",m(function(){g(e,p),"fixed"===f&&(l.position="")})):S&&(s.state="stuck",m(function(){g(e,p,y),"fixed"!==f||c||(l.top="",l.bottom="0",l.position="absolute")}));var w=v>=a&&v<=r;return v<a||v>r?m(function(){g(e,h)}):w&&m(function(){g(e,"stub",h)}),s},s.update=function(){for(var t=0;t<this.instances.length;t+=1){var s=this.instances[t];this.computeScrollOffsets(s)}return this},s.removeInstance=function(t){var s=t.el,e=t.props,i=this.toggleClasses;s.style.position="",s.style[e.verticalPosition]="",i(s,e.stickyClass),i(s,e.stuckClass),i(s.parentNode,e.parentClass)},s.cleanup=function(){for(var t=0;t<this.instances.length;t+=1){var s=this.instances[t];s.props.scrollEl.removeEventListener("scroll",s.stateContainer),this.removeInstance(s)}this.manageState=!1,this.instances=[]},t}();return function(s,e){return new t(s,e)}});
diff --git a/dist/umbrella.stickybits.js b/dist/umbrella.stickybits.js
index cb354663..8e8ec238 100644
--- a/dist/umbrella.stickybits.js
+++ b/dist/umbrella.stickybits.js
@@ -1,6 +1,6 @@
 /**
   stickybits - Stickybits is a lightweight alternative to `position: sticky` polyfills
-  @version v3.3.1
+  @version v3.3.2
   @link https://github.com/dollarshaveclub/stickybits#readme
   @author Jeff Wainwright <yowainwright@gmail.com> (https://jeffry.in)
   @license MIT
@@ -56,6 +56,7 @@
     - .definePosition = defines sticky or fixed
     - .addInstance = an array of objects for each Stickybits Target
     - .getClosestParent = gets the parent for non-window scroll
+    - .getOffsetTop = gets the element offsetTop from the top level of the DOM
     - .computeScrollOffsets = computes scroll position
     - .toggleClasses = older browser toggler
     - .manageState = manages sticky state
@@ -68,7 +69,7 @@
   function () {
     function Stickybits(target, obj) {
       var o = typeof obj !== 'undefined' ? obj : {};
-      this.version = '3.3.1';
+      this.version = '3.3.2';
       this.userAgent = window.navigator.userAgent || 'no `userAgent` provided by the browser';
       this.props = {
         customStickyChangeNumber: o.customStickyChangeNumber || null,
@@ -208,6 +209,24 @@
 
       return p;
     };
+    /*
+      --------
+      getOffsetTop
+      --------
+      - a helper function that gets the offsetTop of the element
+      - from the top level of the DOM
+    */
+
+
+    _proto.getOffsetTop = function getOffsetTop(el) {
+      var offsetTop = 0;
+
+      do {
+        offsetTop = el.offsetTop + offsetTop;
+      } while (el = el.offsetParent);
+
+      return offsetTop;
+    };
     /*
       computeScrollOffsets 📊
       ---
@@ -226,8 +245,8 @@
       var parent = it.parent;
       var isCustom = !this.isWin && p.positionVal === 'fixed';
       var isBottom = p.verticalPosition !== 'bottom';
-      var scrollElOffset = isCustom ? p.scrollEl.getBoundingClientRect().top : 0;
-      var stickyStart = isCustom ? parent.getBoundingClientRect().top - scrollElOffset : parent.getBoundingClientRect().top;
+      var scrollElOffset = isCustom ? this.getOffsetTop(p.scrollEl) : 0;
+      var stickyStart = isCustom ? this.getOffsetTop(parent) - scrollElOffset : this.getOffsetTop(parent);
       var stickyChangeOffset = p.customStickyChangeNumber !== null ? p.customStickyChangeNumber : el.offsetHeight;
       it.offset = scrollElOffset + p.stickyBitStickyOffset;
       it.stickyStart = isBottom ? stickyStart - it.offset : 0;
diff --git a/jsconfig.json b/jsconfig.json
new file mode 100644
index 00000000..f408cac8
--- /dev/null
+++ b/jsconfig.json
@@ -0,0 +1 @@
+{"compilerOptions":{"target":"es6","experimentalDecorators":true},"exclude":["node_modules","bower_components","tmp","vendor",".git","dist"]}
\ No newline at end of file
diff --git a/package-lock.json b/package-lock.json
index b2703a5f..a5a29d35 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "stickybits",
-  "version": "3.3.0",
+  "version": "3.3.2",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -9283,9 +9283,9 @@
       }
     },
     "rollup": {
-      "version": "0.58.0",
-      "resolved": "https://registry.npmjs.org/rollup/-/rollup-0.58.0.tgz",
-      "integrity": "sha512-xu49WFv3R9CkXpRHxKH19PV7dV493XYkhQgIsGJfh7DGqKOp//NKoGjiCSK3reIFTX6PRGzXzQ2nPeVyXKr1Jg==",
+      "version": "0.58.2",
+      "resolved": "https://registry.npmjs.org/rollup/-/rollup-0.58.2.tgz",
+      "integrity": "sha512-RZVvCWm9BHOYloaE6LLiE/ibpjv1CmI8F8k0B0Cp+q1eezo3cswszJH1DN0djgzSlo0hjuuCmyeI+1XOYLl4wg==",
       "dev": true,
       "requires": {
         "@types/estree": "0.0.38",
diff --git a/package.json b/package.json
index 11691ea8..2da45583 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "stickybits",
-  "version": "3.3.1",
+  "version": "3.3.2",
   "description": "Stickybits is a lightweight alternative to `position: sticky` polyfills",
   "main": "dist/stickybits.js",
   "module": "dist/stickybits.es.js",
diff --git a/tests/unit/test.stickybits.js b/tests/unit/test.stickybits.js
index 47c5eb25..603746e2 100644
--- a/tests/unit/test.stickybits.js
+++ b/tests/unit/test.stickybits.js
@@ -112,6 +112,16 @@ test('stickybits .getClosestParent interface', () => {
   expect(parent.id).toBe('parent')
 })
 
+test('stickybits .getOffsetTop interface', () => {
+  // Set up our document
+  document.body.innerHTML = '<div id="parent"><div><div id="child"><div id="manage-sticky"></div></div></div></div>'
+  const child = document.getElementById('child')
+  const parentEl = document.getElementById('parent')
+  const stickybit = stickybits('#manage-sticky')
+  const parentOffsetTop = stickybit.getOffsetTop(parentEl)
+  expect(parentOffsetTop).toBe(0)
+})
+
 test('stickybits .computeScrollOffsets interface', () => {
   // Set up our document
   document.body.innerHTML = '<div id="parent"><div id="manage-sticky"></div></div>'