diff --git a/pyproject.toml b/pyproject.toml
index 45c32a00..29ac399f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,7 +37,7 @@ dependencies = [
     "numpy",
     "tqdm",
     "monty",
-    "pymatgen>=2023.9.10",
+    "pymatgen==2023.9.10",
     "mp-api",
     "ase"
 ]