diff --git a/HISTORY.md b/HISTORY.md
index 06d34a5..00af72d 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,3 +1,8 @@
+unreleased
+==========
+
+  * Fix encoding `%` as last character
+
 1.0.1 / 2016-06-09
 ==================
 
diff --git a/index.js b/index.js
index ae77cc9..fc4906c 100644
--- a/index.js
+++ b/index.js
@@ -19,7 +19,7 @@ module.exports = encodeUrl
  * @private
  */
 
-var ENCODE_CHARS_REGEXP = /(?:[^\x21\x25\x26-\x3B\x3D\x3F-\x5B\x5D\x5F\x61-\x7A\x7E]|%(?:[^0-9A-Fa-f]|[0-9A-Fa-f][^0-9A-Fa-f]))+/g
+var ENCODE_CHARS_REGEXP = /(?:[^\x21\x25\x26-\x3B\x3D\x3F-\x5B\x5D\x5F\x61-\x7A\x7E]|%(?:[^0-9A-Fa-f]|[0-9A-Fa-f][^0-9A-Fa-f]|$))+/g
 
 /**
  * RegExp to match unmatched surrogate pair.
diff --git a/test/test.js b/test/test.js
index 5b215ec..b959ca1 100644
--- a/test/test.js
+++ b/test/test.js
@@ -67,7 +67,7 @@ describe('encodeUrl(url)', function () {
     })
 
     it('should encode the "%" if not a valid sequence', function () {
-      assert.equal(encodeUrl('http://localhost/%foo%bar%zap'), 'http://localhost/%25foo%bar%25zap')
+      assert.equal(encodeUrl('http://localhost/%foo%bar%zap%'), 'http://localhost/%25foo%bar%25zap%25')
     })
   })