diff --git a/pyproject.toml b/pyproject.toml
index fb34eb3d..8c04182c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,7 +26,8 @@ dependencies = [
     "PyYaml~=6.0.2",
     "requests",
     "ruamel.yaml",
-    "s3fs",
+    "aiobotocore<3.9.0",
+    "s3fs==2026.4.0",
     "scipy",
     "shapely~=2.1.2",
     "xarray[complete]==2025.12.0",