diff --git a/environment.yml b/environment.yml
index b3d66177..48dac1e8 100644
--- a/environment.yml
+++ b/environment.yml
@@ -3,16 +3,17 @@ channels:
   - conda-forge
 dependencies:
   - python=3.11.6
-  - pip=24.0
-  - numpy
+  - pip
+  - numpy=1.26.4
   - scipy
   - scikit-learn
   - cadquery
-  - moab==5.5.0[build=nompi_tempest_*]
+  - moab=5.5.1[build=nompi_tempest_*]
   - cad_to_dagmc
   - ca-certificates
   - certifi
   - openssl
+  - openmc=0.15.0[build=dagmc_nompi_*]
   - matplotlib
   - pip:
       - netcdf4
diff --git a/parastell/nwl_utils.py b/parastell/nwl_utils.py
index 4a3c9735..f1f97760 100644
--- a/parastell/nwl_utils.py
+++ b/parastell/nwl_utils.py
@@ -5,8 +5,10 @@
 import pystell.read_vmec as read_vmec
 import matplotlib.pyplot as plt
 import concurrent.futures
-from multiprocessing import cpu_count
 import math
+import matplotlib
+
+matplotlib.use("agg")
 
 
 def extract_ss(ss_file):