diff --git a/envs/environment-cpu.yml b/envs/environment-cpu.yml
index d6efa5e5..599fc9a0 100644
--- a/envs/environment-cpu.yml
+++ b/envs/environment-cpu.yml
@@ -18,7 +18,7 @@ dependencies:
   # Tools to work with crystalline and molecular data
   - openbabel==3.1.*
   - rdkit==2023.03.2
-  - pymatgen
+  - pymatgen==2023.8.10
 
   # Use Conda PyTorch to avoid OpenMP disagreement with other libraries
   - pytorch==1.13.*