diff --git a/pyproject.toml b/pyproject.toml
index 31c49c1a9..9877c0300 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -29,7 +29,7 @@ dependencies = [
     "defusedxml==0.7.1",
     "h5py==3.12.1",
     "matplotlib==3.10.0",
-    "mendeleev==0.19.0",
+    "mendeleev==0.20.1",
     "mp-api==0.45.1",
     "numpy==1.26.4",
     "pandas==2.2.3",