diff --git a/jedi/api/__init__.py b/jedi/api/__init__.py
index 7b9dc768..c44c6c25 100644
--- a/jedi/api/__init__.py
+++ b/jedi/api/__init__.py
@@ -135,9 +135,9 @@ class Script(object):
 
         if not dot:
             # add named params
-            for call_def in self.call_signatures():
-                if not isinstance(call_def.module, compiled.CompiledObject):
-                    for p in call_def.params:
+            for call_sig in self.call_signatures():
+                if not isinstance(call_sig.module, compiled.CompiledObject):
+                    for p in call_sig.params:
                         # Allow access on _definition here, because it's a
                         # public API and we don't want to make the internal
                         # Name object public.
@@ -481,7 +481,7 @@ class Script(object):
 
         This would return ``None``.
 
-        :rtype: list of :class:`classes.CallDef`
+        :rtype: list of :class:`classes.CallSignature`
         """
 
         user_stmt = self._parser.user_stmt_with_whitespace()
@@ -494,7 +494,7 @@ class Script(object):
             origins = cache.cache_call_signatures(_callable, user_stmt)
         debug.speed('func_call followed')
 
-        return [classes.CallDef(self._evaluator, o, index, call) for o in origins
+        return [classes.CallSignature(self._evaluator, o, index, call) for o in origins
                 if o.isinstance(er.Function, er.Instance, er.Class)
                 or isinstance(o, compiled.CompiledObject) and o.type() != 'module']
 
diff --git a/jedi/api/classes.py b/jedi/api/classes.py
index ef26c2ba..012d92bf 100644
--- a/jedi/api/classes.py
+++ b/jedi/api/classes.py
@@ -543,9 +543,9 @@ class Definition(BaseDefinition):
         return defined_names(self._evaluator, d)
 
 
-class CallDef(object):
+class CallSignature(object):
     """
-    `CallDef` objects is the return value of `Script.function_definition`.
+    `CallSignature` objects is the return value of `Script.function_definition`.
     It knows what functions you are currently in. e.g. `isinstance(` would
     return the `isinstance` function. without `(` it would return nothing.
     """