diff --git a/jedi/evaluate/arguments.py b/jedi/evaluate/arguments.py
index 2642f487..8f66a6be 100644
--- a/jedi/evaluate/arguments.py
+++ b/jedi/evaluate/arguments.py
@@ -233,8 +233,8 @@ class TreeArguments(AbstractArguments):
                         named_args.append((c[0].value, LazyTreeContext(self.context, c[2]),))
                     else:  # Generator comprehension.
                         # Include the brackets with the parent.
-                        comp = iterable.GeneratorComprehension(
-                            self._evaluator, self.context, self.argument_node.parent)
+                        comp = iterable.ArgumentGeneratorComprehension(
+                            self._evaluator, self.context, el)
                         yield None, LazyKnownContext(comp)
                 else:
                     yield None, LazyTreeContext(self.context, el)
@@ -246,10 +246,10 @@ class TreeArguments(AbstractArguments):
 
     def _as_tree_tuple_objects(self):
         for star_count, argument in unpack_arglist(self.argument_node):
+            default = None
             if argument.type == 'argument':
-                argument, default = argument.children[::2]
-            else:
-                default = None
+                if len(argument.children) == 3:  # Keyword argument.
+                    argument, default = argument.children[::2]
             yield argument, default, star_count
 
     def iter_calling_names_with_star(self):
diff --git a/jedi/evaluate/context/iterable.py b/jedi/evaluate/context/iterable.py
index 6ae64125..4fb30db7 100644
--- a/jedi/evaluate/context/iterable.py
+++ b/jedi/evaluate/context/iterable.py
@@ -127,22 +127,17 @@ class ComprehensionMixin(object):
         self._defining_context = defining_context
         self._atom = atom
 
-    def _get_comprehension(self):
-        "return 'a for a in b'"
-        # The atom contains a testlist_comp
-        return self._atom.children[1]
-
     def _get_comp_for(self):
-        "return CompFor('for a in b')"
-        return self._get_comprehension().children[1]
+        """return CompFor('for a in b')"""
+        return self._atom.children[1].children[1]
 
-    def _eval_node(self, index=0):
+    def _entry_node(self):
         """
         The first part `x + 1` of the list comprehension:
 
             [x + 1 for x in foo]
         """
-        return self._get_comprehension().children[index]
+        return self._atom.children[1].children[0]
 
     @evaluator_method_cache()
     def _get_comp_for_context(self, parent_context, comp_for):
@@ -174,9 +169,9 @@ class ComprehensionMixin(object):
                     for result in self._nested(comp_fors[1:], context_):
                         yield result
                 except IndexError:
-                    iterated = context_.eval_node(self._eval_node())
+                    iterated = context_.eval_node(self._entry_node())
                     if self.array_type == 'dict':
-                        yield iterated, context_.eval_node(self._eval_node(2))
+                        yield iterated, context_.eval_node(self._value_node())
                     else:
                         yield iterated
 
@@ -253,7 +248,10 @@ class DictComprehension(_DictMixin, ComprehensionMixin, Sequence):
     array_type = u'dict'
 
     def _get_comp_for(self):
-        return self._get_comprehension().children[3]
+        return self._atom.children[1].children[3]
+
+    def _value_node(self):
+        return self._atom.children[1].children[2]
 
     def py__iter__(self, contextualized_node=None):
         for keys, values in self._iterate():
@@ -307,6 +305,16 @@ class GeneratorComprehension(ComprehensionMixin, GeneratorBase):
     pass
 
 
+class ArgumentGeneratorComprehension(ComprehensionMixin, GeneratorBase):
+    def _get_comp_for(self):
+        # Not actually an atom. But need to correct this comprehension madness
+        # anyway.
+        return self._atom.children[1]
+
+    def _entry_node(self):
+        return self._atom.children[0]
+
+
 class SequenceLiteralContext(Sequence):
     _TUPLE_LIKE = 'testlist_star_expr', 'testlist', 'subscriptlist'
     mapping = {'(': u'tuple',
diff --git a/test/completion/comprehensions.py b/test/completion/comprehensions.py
index b2da01bc..e66858e0 100644
--- a/test/completion/comprehensions.py
+++ b/test/completion/comprehensions.py
@@ -223,3 +223,33 @@ next(iter({a for a in range(10)}))
 [int(str(x.value) for x in list
 
 def reset_missing_bracket(): pass
+
+
+# -----------------
+# function calls
+# -----------------
+
+def foo(arg):
+    return arg
+
+
+x = foo(x for x in [1])
+
+#? int()
+next(x)
+#?
+x[0]
+
+# While it's illegal to have more than one argument, when a generator
+# expression is involved, it's still a valid parse tree and Jedi should still
+# work (and especially not raise Exceptions). It's debatable wheter inferring
+# values for invalid statements is a good idea, but not failing is a must.
+
+#? int()
+next(foo(x for x in [1], 1))
+
+def bar(x, y):
+    return y
+
+#? str()
+next(bar(x for x in [1], x for x in ['']))