diff --git a/setup.py b/setup.py
index 1571f2bfb5a55d7b0a65022bf5f243e0a70af2b1..ed32405e697839a4c451a62e5b0aba4a6572759a 100644
--- a/setup.py
+++ b/setup.py
@@ -38,6 +38,7 @@ setup(
         "pytools>=2021.1",
         "immutables",
         "attrs",
+        "bidict",
         ],
     package_data={"pytato": ["py.typed"]},
     author="Andreas Kloeckner, Matt Wala, Xiaoyu Wei",