diff --git a/test/tests/utilitiesTest.js b/test/tests/utilitiesTest.js
index fa4e00a..2cc21c7 100644
--- a/test/tests/utilitiesTest.js
+++ b/test/tests/utilitiesTest.js
@@ -99,7 +99,7 @@ describe("Zotero.Utilities", function() {
 			assert.equal(cleanDOI(`Foo bar ${encodedUri}. Foo bar`), expected);
 		});
 
-		it("should parse a DOI with url encoded params", function () {
+		it("should parse a DOI URL with encoded characters", function () {
 			const encodedUri = "https://doi.org/10.1002/1096-9128(200005)12:6%3C375::AID-CPE480%3E3.0.CO;2-M";
 			const expected = "10.1002/1096-9128(200005)12:6<375::AID-CPE480>3.0.CO;2-M";
 			assert.equal(cleanDOI(`Foo bar ${encodedUri}. Foo bar`), expected);
diff --git a/utilities.js b/utilities.js
index 21f36ec..14ea081 100644
--- a/utilities.js
+++ b/utilities.js
@@ -499,11 +499,11 @@ var Utilities = {
 		var result = doi[0];
 
 		// Check if the DOI ends with a bracket
-		const trailingBracket = result.slice(-1);
+		var trailingBracket = result.slice(-1);
 		if ([']', ')', '}'].includes(trailingBracket)) {
 			// Check the portion of the string before the matched DOI for an unclosed bracket
-			const beforeDOI = x.slice(0, doi.index);
-			const openingBracket = {
+			let beforeDOI = x.slice(0, doi.index);
+			let openingBracket = {
 				']': '[',
 				')': '(',
 				'}': '{'