diff --git a/pyproject.toml b/pyproject.toml
index fcfd8457..af8bae5f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -51,7 +51,7 @@ dev = [
     "coverage",
     "ruff",
     "coveralls",
-    "pymatgen",
+    "pymatgen>=2024.2.20",
     "sphinx",
     "sphinx_rtd_theme",
     "sphinxcontrib-bibtex",