diff --git a/setup.py b/setup.py
index a68c383cdb1cf55eaa79b39df1951cd4517cb248..d3aa27d77b7b18e0553b5688525ae780c47393e7 100755
--- a/setup.py
+++ b/setup.py
@@ -137,7 +137,7 @@ if __name__ == "__main__":
             "panel",
             "colorcet",
             # 0.20.28 has this issue: https://github.com/pola-rs/polars/issues/16442
-            "polars >= 0.20.16, != 0.20.28",
+            "polars >= 0.20.16, != 0.20.28, < 1.0.0",
             # Pandas >= 1.0.0 has support for new nullable dtypes
             # Pandas 1.2.0 has broken barplots:
             # https://github.com/pandas-dev/pandas/issues/38947