diff --git a/lib/xml-stream.js b/lib/xml-stream.js
index 7121ffd..5d0e490 100644
--- a/lib/xml-stream.js
+++ b/lib/xml-stream.js
@@ -536,7 +536,7 @@ function parse() {
       preludeBuffers.push(data);
       prelude += data.toString();
       if (/^\s*<[^>]+>/.test(prelude)) {
-        var matches = prelude.match(/^\s*<\?xml[^>]+encoding="(.+?)"[^>]*\?>/);
+        var matches = prelude.match(/^\s*<\?xml[^>]+encoding=['"](.+?)['"][^>]*\?>/);
         self._encoding = matches ? matches[1] : 'utf8';
         self._encoder = makeEncoder(self._encoding);
         for (var i = 0, n = preludeBuffers.length; i < n; i++) {