diff --git a/lib/checks/label/label-content-name-mismatch.js b/lib/checks/label/label-content-name-mismatch.js
index 50c6ea9605..230b95dd4f 100644
--- a/lib/checks/label/label-content-name-mismatch.js
+++ b/lib/checks/label/label-content-name-mismatch.js
@@ -1,5 +1,5 @@
 const { text } = axe.commons;
-const { pixelThreshold, occuranceThreshold } = options || {};
+const { differenceThreshold, occuranceThreshold } = options || {};
 
 const accText = text.accessibleText(node).toLowerCase();
 if (text.isHumanInterpretable(accText) < 1) {
@@ -10,7 +10,7 @@ const textVNodes = text.visibleTextNodes(virtualNode);
 const nonLigatureText = textVNodes
 	.filter(
 		textVNode =>
-			!text.isIconLigature(textVNode, pixelThreshold, occuranceThreshold)
+			!text.isIconLigature(textVNode, differenceThreshold, occuranceThreshold)
 	)
 	.map(textVNode => textVNode.actualNode.nodeValue)
 	.join('');
diff --git a/lib/checks/label/label-content-name-mismatch.json b/lib/checks/label/label-content-name-mismatch.json
index a8da4c1a26..27cd238e88 100644
--- a/lib/checks/label/label-content-name-mismatch.json
+++ b/lib/checks/label/label-content-name-mismatch.json
@@ -2,7 +2,7 @@
 	"id": "label-content-name-mismatch",
 	"evaluate": "label-content-name-mismatch.js",
 	"options": {
-		"pixelThreshold": 0.1,
+		"differenceThreshold": 0.15,
 		"occuranceThreshold": 3
 	},
 	"metadata": {
diff --git a/lib/commons/text/is-icon-ligature.js b/lib/commons/text/is-icon-ligature.js
index 772574f50c..030737acc9 100644
--- a/lib/commons/text/is-icon-ligature.js
+++ b/lib/commons/text/is-icon-ligature.js
@@ -159,9 +159,7 @@ text.isIconLigature = function(
 	context.textAlign = 'left';
 	context.textBaseline = 'top';
 	context.fillText(firstChar, 0, 0);
-	const compareData = new Uint32Array(
-		context.getImageData(0, 0, width, fontSize).data.buffer
-	);
+	const compareData = context.getImageData(0, 0, width, fontSize).data;
 
 	// if the font doesn't even have character data for a single char then
 	// it has to be an icon ligature (e.g. Material Icon)
@@ -172,21 +170,25 @@ text.isIconLigature = function(
 
 	context.clearRect(0, 0, width, fontSize);
 	context.fillText(nodeValue, 0, 0);
-	const compareWith = new Uint32Array(
-		context.getImageData(0, 0, width, fontSize).data.buffer
-	);
+	const compareWith = context.getImageData(0, 0, width, fontSize).data;
 
 	// calculate the number of differences between the first letter and the
-	// entire string, ignoring color differences
-	const differences = compareData.reduce((diff, pixel, i) => {
-		if (pixel === 0 && compareWith[i] === 0) {
-			return diff;
+	// entire string
+	let differences = 0;
+	const size = compareWith.length / 4;
+	for (let i = 0; i < compareWith.length; i += 4) {
+		// ignore color differences, only deal with pixel placement differences
+		let compareDataHasPixel = false;
+		let compareWithHasPixel = false;
+		for (let j = 0; j < 4; j++) {
+			compareDataHasPixel = compareDataHasPixel || !!compareData[i + j];
+			compareWithHasPixel = compareWithHasPixel || !!compareWith[i + j];
 		}
-		if (pixel !== 0 && compareWith[i] !== 0) {
-			return diff;
+
+		if (compareDataHasPixel !== compareWithHasPixel) {
+			differences++;
 		}
-		return ++diff;
-	}, 0);
+	}
 
 	// calculate the difference between the width of each character and the
 	// combined with of all characters
@@ -195,7 +197,7 @@ text.isIconLigature = function(
 	}, 0);
 	const actualWidth = context.measureText(nodeValue).width;
 
-	const pixelDifference = differences / compareData.length;
+	const pixelDifference = differences / size;
 	const sizeDifference = 1 - actualWidth / expectedWidth;
 
 	if (
diff --git a/lib/core/imports/index.js b/lib/core/imports/index.js
index 1eb9d0440b..05575cb64b 100644
--- a/lib/core/imports/index.js
+++ b/lib/core/imports/index.js
@@ -14,10 +14,6 @@ if (!('Promise' in window)) {
 	require('es6-promise').polyfill();
 }
 
-if (!('Uint32Array' in window)) {
-	require('core-js/features/typed-array/uint32-array');
-}
-
 /**
  * Polyfill `WeakMap`
  * Reference: https://github.com/polygonplanet/weakmap-polyfill
diff --git a/package.json b/package.json
index 11007453f2..f8d76030e6 100644
--- a/package.json
+++ b/package.json
@@ -87,7 +87,6 @@
 		"browserify": "^16.2.3",
 		"chai": "~4.2.0",
 		"clone": "~2.1.1",
-		"core-js": "^3.2.1",
 		"css-selector-parser": "^1.3.0",
 		"derequire": "^2.0.6",
 		"emoji-regex": "8.0.0",