diff --git a/bec_lib/pyproject.toml b/bec_lib/pyproject.toml
index 2a841e0ae..840edba45 100644
--- a/bec_lib/pyproject.toml
+++ b/bec_lib/pyproject.toml
@@ -30,7 +30,7 @@ dependencies = [
     "rich>=13.7,<16.0",
     "scipy~=1.12",
     "tomli~=2.0, >=2.0.1",
-    "toolz~=0.12",
+    "toolz>=0.12,<2.0",
     "typeguard ~= 4.1, >=4.1.5",
     "prettytable~=3.9",
     "h5py~=3.10",