diff --git a/test/test_uri.py b/test/test_uri.py
index a65d38d..69fabb7 100644
--- a/test/test_uri.py
+++ b/test/test_uri.py
@@ -278,7 +278,7 @@ def test_empty_protocol_assignment(self, empty):
 		assert empty.scheme == 'http'
 		
 		empty.scheme = None
-		assert str(empty) == "example.com/over/there"
+		assert str(empty) == "//example.com/over/there"
 	
 	def test_bad_assignment(self, empty):
 		with pytest.raises(AttributeError):
diff --git a/uri/part/scheme.py b/uri/part/scheme.py
index 150e065..6134385 100644
--- a/uri/part/scheme.py
+++ b/uri/part/scheme.py
@@ -37,6 +37,9 @@ def render(self, obj, value):
 		if obj._scheme and obj.scheme.slashed:
 			result = result + '//'
 		
+		if not obj._scheme and obj.authority:
+			result = '//'
+		
 		return result
 	
 	def __get__(self, obj, cls=None):
diff --git a/uri/part/uri.py b/uri/part/uri.py
index 0d8ac8e..3c8d958 100644
--- a/uri/part/uri.py
+++ b/uri/part/uri.py
@@ -22,9 +22,6 @@ def __get__(self, obj, cls=None):
 			value = getattr(obj, part)
 			part = getattr(cls, part)
 			
-			if value is None:
-				continue
-			
 			components.append(part.render(obj, value))
 		
 		return "".join(components)