diff --git a/jedi/evaluate/compiled/fake.py b/jedi/evaluate/compiled/fake.py
index 6242483d..0037cfc7 100644
--- a/jedi/evaluate/compiled/fake.py
+++ b/jedi/evaluate/compiled/fake.py
@@ -100,8 +100,10 @@ def _faked(module, obj, name):
 def get_faked(module, obj, name=None):
     obj = obj.__class__ if is_class_instance(obj) else obj
     result = _faked(module, obj, name)
-    # TODO may this ever happen? result None? if so, document!
-    if not isinstance(result, pt.Class) and result is not None:
+    if result is None or isinstance(result, pt.Class):
+        # We're not interested in classes. What we want is functions.
+        return None
+    else:
         # Set the docstr which was previously not set (faked modules don't
         # contain it).
         doc = '"""%s"""' % obj.__doc__  # TODO need escapes.
diff --git a/jedi/evaluate/compiled/fake/io.pym b/jedi/evaluate/compiled/fake/io.pym
index 8225477a..87b02eed 100644
--- a/jedi/evaluate/compiled/fake/io.pym
+++ b/jedi/evaluate/compiled/fake/io.pym
@@ -1,3 +1,6 @@
 class TextIOWrapper():
     def __next__(self):
-        return 'hacked io return'
+        return str()
+
+    def __iter__(self):
+        yield str()
diff --git a/test/completion/basic.py b/test/completion/basic.py
index 97155bcc..8337b8dd 100644
--- a/test/completion/basic.py
+++ b/test/completion/basic.py
@@ -143,6 +143,9 @@ ret()[0]
 with open('') as f:
     #? ['closed']
     f.closed
+    for line in f:
+        #? str()
+        line
 
 with open('') as f1, open('') as f2:
     #? ['closed']