diff --git a/src/main.js b/src/main.js
index 8f6dd14..32575c5 100644
--- a/src/main.js
+++ b/src/main.js
@@ -1,9 +1,52 @@
+function b64decode(data) {
+	let length = (data.length >> 2) * 3;
+	if (data.length % 4)
+		length += (data.length % 4) - 1;
+
+	const alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_';
+
+	const table = []
+	for (let i = 0; i < alphabet.length; i++)
+		table[alphabet.charCodeAt(i)] = i;
+
+	const result = new Uint8Array(length);
+	for (let i = 0; i < data.length / 4; i++) {
+		const value =
+			(table[data.charCodeAt(4 * i + 0)] << 18) |
+			(table[data.charCodeAt(4 * i + 1)] << 12) |
+			(table[data.charCodeAt(4 * i + 2)] <<  6) |
+			(table[data.charCodeAt(4 * i + 3)] <<  0);
+
+		result[3 * i + 0] = value >> 16;
+		result[3 * i + 1] = value >>  8;
+		result[3 * i + 2] = value >>  0;
+	}
+
+	if (data.length % 4 == 2) {
+		const value =
+			(table[data.charCodeAt(data.length - 2)] <<  6) |
+			(table[data.charCodeAt(data.length - 1)] <<  0);
+		result[result.length - 1] = value >> 4;
+	}
+
+	if (data.length % 4 == 3) {
+		const value =
+			(table[data.charCodeAt(data.length - 3)] << 12) |
+			(table[data.charCodeAt(data.length - 2)] <<  6) |
+			(table[data.charCodeAt(data.length - 1)] <<  0);
+		result[result.length - 2] = value >> 10;
+		result[result.length - 1] = value >>  2;
+	}
+
+	return result;
+}
+
 window.addEventListener('load', function() {
 	const base64 = window.location.hash.substring(1)
 
-	const zlib = Uint8Array.fromBase64(base64, { alphabet: 'base64url' });
+	const zlib = b64decode(base64);
 
-	const uncompressed = pako.inflate(new Uint8Array(zlib));
+	const uncompressed = pako.inflate(zlib);
 
 	let decoded = new TextDecoder().decode(uncompressed);