diff --git a/index.js b/index.js
index cb03219..61615f1 100644
--- a/index.js
+++ b/index.js
@@ -4,6 +4,7 @@ var path = require('path');
 var isglob = require('is-glob');
 
 module.exports = function globParent(str) {
-	while (isglob(str)) str = path.dirname(str);
+	str += 'a'; // preserves full path in case of trailing path separator
+	do {str = path.dirname(str)} while (isglob(str));
 	return str;
 };