diff --git a/CHANGES.rst b/CHANGES.rst
index 952178e39..8f985ff45 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,6 +1,11 @@
 CHANGES
 =======
 
+1.1.1 (2018-02-17)
+------------------
+
+* Fix performance regression: don't encode enmpty netloc (#170)
+
 1.1.0 (2018-01-21)
 ------------------
 
diff --git a/yarl/__init__.py b/yarl/__init__.py
index 4227f44eb..f8a685735 100644
--- a/yarl/__init__.py
+++ b/yarl/__init__.py
@@ -196,8 +196,11 @@ def build(cls, *, scheme='', user='', password='', host='', port=None,
             raise ValueError(
                 "Only one of \"query\" or \"query_string\" should be passed")
 
-        netloc = cls._make_netloc(user, password, host, port,
-                                  encode=not encoded)
+        if not user and not password and not host and not port:
+            netloc = ''
+        else:
+            netloc = cls._make_netloc(user, password, host, port,
+                                      encode=not encoded)
         if not encoded:
             path = cls._PATH_QUOTER(path)
             if netloc: