diff --git a/index.js b/index.js
index a49ee5a..f4e0feb 100644
--- a/index.js
+++ b/index.js
@@ -22,18 +22,11 @@ module.exports = encodeUrl
 var ENCODE_CHARS_REGEXP = /(?:[^\x21\x23-\x3B\x3D\x3F-\x5F\x61-\x7A\x7C\x7E]|%(?:[^0-9A-Fa-f]|[0-9A-Fa-f][^0-9A-Fa-f]|$))+/g
 
 /**
- * RegExp to match unmatched surrogate pair.
+ * RegExp to match surrogate pairs and unpaired surrogates.
  * @private
  */
 
-var UNMATCHED_SURROGATE_PAIR_REGEXP = /(^|[^\uD800-\uDBFF])[\uDC00-\uDFFF]|[\uD800-\uDBFF]([^\uDC00-\uDFFF]|$)/g
-
-/**
- * String to replace unmatched surrogate pair with.
- * @private
- */
-
-var UNMATCHED_SURROGATE_PAIR_REPLACE = '$1\uFFFD$2'
+var SURROGATE_REGEXP = /([\uD800-\uDBFF][\uDC00-\uDFFF])|[\uD800-\uDFFF]/g
 
 /**
  * Encode a URL to a percent-encoded form, excluding already-encoded sequences.
@@ -55,6 +48,8 @@ var UNMATCHED_SURROGATE_PAIR_REPLACE = '$1\uFFFD$2'
 
 function encodeUrl (url) {
   return String(url)
-    .replace(UNMATCHED_SURROGATE_PAIR_REGEXP, UNMATCHED_SURROGATE_PAIR_REPLACE)
+    .replace(SURROGATE_REGEXP, function (match, pair) {
+      return pair || '\uFFFD'
+    })
     .replace(ENCODE_CHARS_REGEXP, encodeURI)
 }
diff --git a/test/test.js b/test/test.js
index 3601cf6..55ec5a9 100644
--- a/test/test.js
+++ b/test/test.js
@@ -85,6 +85,18 @@ describe('encodeUrl(url)', function () {
         assert.strictEqual(encodeUrl('http://localhost/\uD83Dfoo\uDC7B <\uDC7B\uD83D>.html'), 'http://localhost/%EF%BF%BDfoo%EF%BF%BD%20%3C%EF%BF%BD%EF%BF%BD%3E.html')
       })
 
+      it('should replace consecutive unpaired high surrogates', function () {
+        assert.strictEqual(encodeUrl('\uD800\uD800\uD800'), '%EF%BF%BD%EF%BF%BD%EF%BF%BD')
+      })
+
+      it('should replace consecutive unpaired low surrogates', function () {
+        assert.strictEqual(encodeUrl('\uDC00\uDC00\uDC00'), '%EF%BF%BD%EF%BF%BD%EF%BF%BD')
+      })
+
+      it('should preserve a valid pair next to unpaired surrogates', function () {
+        assert.strictEqual(encodeUrl('\uD800\uD83D\uDC7B\uDC00'), '%EF%BF%BD%F0%9F%91%BB%EF%BF%BD')
+      })
+
       it('should encode at end of string', function () {
         assert.strictEqual(encodeUrl('http://localhost/\uD83D'), 'http://localhost/%EF%BF%BD')
       })