diff --git a/pyproject.toml b/pyproject.toml
index 4520b23f..be12f583 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,7 @@ dependencies = [
     "scipy",
     "xarray",
     "jax",
-    "capytaine",
+    "capytaine==2.3.1",
     "joblib",
     "wavespectra>=4.0",
     "netcdf4",