diff --git a/jedi/api/__init__.py b/jedi/api/__init__.py
index 8c2de1e3..ebe890ea 100644
--- a/jedi/api/__init__.py
+++ b/jedi/api/__init__.py
@@ -669,7 +669,7 @@ def defined_names(source, path=None, encoding='utf-8'):
         common.source_to_unicode(source, encoding),
         module_path=path,
     )
-    return classes._defined_names(Evaluator(), parser.module)
+    return classes.defined_names(Evaluator(), parser.module)
 
 
 def preload_module(*modules):
diff --git a/jedi/api/classes.py b/jedi/api/classes.py
index 9a08df37..341882f2 100644
--- a/jedi/api/classes.py
+++ b/jedi/api/classes.py
@@ -537,10 +537,10 @@ class Definition(BaseDefinition):
             d = d.var
         if isinstance(d, pr.Name):
             d = d.parent
-        return _defined_names(self._evaluator, d)
+        return defined_names(self._evaluator, d)
 
 
-def _defined_names(evaluator, scope):
+def defined_names(evaluator, scope):
     """
     List sub-definitions (e.g., methods in class).