diff --git a/Lib/ast.py b/Lib/ast.py
index 0b8baf7..092f077 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -58,6 +58,8 @@
             return tuple(map(_convert, node.elts))
         elif isinstance(node, List):
             return list(map(_convert, node.elts))
+        elif isinstance(node, Set):
+            return set(map(_convert, node.elts))
         elif isinstance(node, Dict):
             return dict((_convert(k), _convert(v)) for k, v
                         in zip(node.keys, node.values))