diff --git a/pyproject.toml b/pyproject.toml
index fa6d9d4..003263e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,7 @@ classifiers = [
   'Topic :: Scientific/Engineering :: Astronomy',
   'Topic :: Scientific/Engineering :: Physics'
 ]
-dependencies = ["numpy>=1.21.2", "scipy"]
+dependencies = ["numpy>=1.21.2", "numpy<2.0.0", "scipy"]
 dynamic = ["version", "description"]
 keywords = ["python", "science", "astronomy", "astrophysics", "IceCube", "neutrino", "simulation"]
 license = {file = "LICENSES/BSD-2-Clause.txt"}
diff --git a/src/simweights/_genie_weighter.py b/src/simweights/_genie_weighter.py
index 75d668c..938149c 100644
--- a/src/simweights/_genie_weighter.py
+++ b/src/simweights/_genie_weighter.py
@@ -55,6 +55,7 @@ def GenieWeighter(file_obj: Any) -> Weighter:  # noqa: N802
     weighter = Weighter([file_obj], surface)
     weighter.add_weight_column("pdgid", weighter.get_column("I3GenieResult", "neu").astype(np.int32))
     weighter.add_weight_column("energy", weighter.get_column("I3GenieResult", "Ev"))
+    weighter.add_weight_column("cos_zen", weighter.get_column("I3GenieResult", "pzv"))
     weighter.add_weight_column("wght", weighter.get_column("I3GenieResult", "wght"))
 
     return weighter