diff --git a/jedi/evaluate/iterable.py b/jedi/evaluate/iterable.py
index fe8f587e..c6aafc91 100644
--- a/jedi/evaluate/iterable.py
+++ b/jedi/evaluate/iterable.py
@@ -37,9 +37,14 @@ class IterableWrapper(tree.Base):
 
     @memoize_default()
     def _get_names_dict(self, names_dict):
-        try:
-            builtin_methods = self.builtin_methods
-        except AttributeError:
+        builtin_methods = {}
+        for cls in type(self).mro():
+            try:
+                builtin_methods = dict(builtin_methods, **cls.builtin_methods)
+            except AttributeError:
+                pass
+
+        if not builtin_methods:
             return names_dict
 
         dct = {}
@@ -276,6 +281,10 @@ class DictComprehension(Comprehension, ArrayMixin):
     def _get_comp_for(self):
         return self._get_comprehension().children[3]
 
+    def py__iter__(self):
+        for keys, values in self._iterate():
+            yield keys
+
     def py__getitem__(self, index):
         for keys, values in self._iterate():
             for k in keys:
diff --git a/test/completion/comprehensions.py b/test/completion/comprehensions.py
index 83dba5da..78e4f4b3 100644
--- a/test/completion/comprehensions.py
+++ b/test/completion/comprehensions.py
@@ -132,7 +132,7 @@ list({a - 1: 3 for a in [1]})[0]
 d = {a - 1: b for a, b in {1: 'a', 3: 1.0}.items()}
 #? int()
 list(d)[0]
-#? str()
+#? str() float()
 d.values()[0]
 #? str()
 d[0]
diff --git a/test/completion/types.py b/test/completion/types.py
index 9c3125f0..768b6602 100644
--- a/test/completion/types.py
+++ b/test/completion/types.py
@@ -86,9 +86,9 @@ d.values()[0]
 ##? int() list
 dict(d).values()[0]
 
-#? str() float()
+#? str()
 d.items()[0][0]
-#? int() list
+#? int()
 d.items()[0][1]
 
 # -----------------