diff --git a/index.js b/index.js
index 96e0431..34113f8 100644
--- a/index.js
+++ b/index.js
@@ -5,7 +5,7 @@ const normalizeUrl = require('normalize-url');
 
 const getUrlsFromQueryParams = url => {
 	const ret = new Set();
-	const {searchParams} = (new URL(url.replace(/^(\/\/|(www\.))/, 'http://$2')));
+	const {searchParams} = (new URL(url.replace(/^(\/\/|(www\.))/i, 'http://$2')));
 
 	for (const [, value] of searchParams) {
 		if (urlRegex({exact: true}).test(value)) {
diff --git a/test.js b/test.js
index 0e60165..127b9f5 100644
--- a/test.js
+++ b/test.js
@@ -130,3 +130,11 @@ test('requireSchemeOrWww turned off', t => {
 		])
 	);
 });
+
+test('supports upper case URL', t => {
+	const url = 'WWW.POS.COM';
+
+	t.notThrows(() => {
+		getUrls(url, {extractFromQueryString: true});
+	});
+});