diff --git a/jedi/evaluate/__init__.py b/jedi/evaluate/__init__.py
index 26f3e6a6..041563f0 100644
--- a/jedi/evaluate/__init__.py
+++ b/jedi/evaluate/__init__.py
@@ -339,6 +339,9 @@ class Evaluator(object):
                 pass
             else:
                 if isinstance(comp_for, tree.CompFor):
+                    if atom.children[0] == '{':
+                        # TODO dict/set comprehensions should be working.
+                        return []
                     return set([iterable.Comprehension.from_atom(self, atom)])
             return set([iterable.Array(self, atom)])
 
diff --git a/test/completion/comprehensions.py b/test/completion/comprehensions.py
index c36ed6da..bec04689 100644
--- a/test/completion/comprehensions.py
+++ b/test/completion/comprehensions.py
@@ -47,9 +47,6 @@ left
 #? str()
 [a for a in {1:'x'}][0]
 
-##? str()
-{a-1:b for a,b in {1:'a', 3:1.0}.items()}[0]
-
 # list comprehensions should also work in combination with functions
 def listen(arg):
     for x in arg:
@@ -118,6 +115,16 @@ left
 #? int()
 right
 
+# -----------------
+# set comprehensions
+# -----------------
+
+##? str()
+{a - 1: b for a, b in {1: 'a', 3: 1.0}.items()}[0]
+
+#?
+{a - 1 for a in [1]}
+
 # -----------------
 # name resolution in comprehensions.
 # -----------------
@@ -127,3 +134,5 @@ def x():
     #? 22
     [a for a in h if hio]
     if hio: pass
+
+