diff --git a/pyproject.toml b/pyproject.toml
index ab15c7eb..317b4fea 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -74,7 +74,7 @@ plot = [
   "plotly",
 ]
 test = [
-  "aeon",
+  "aeon<0.5.0",
   "coverage[toml]",
   "fastapi",
   "joblib",