diff --git a/pkgs/development/python-modules/pymatgen/default.nix b/pkgs/development/python-modules/pymatgen/default.nix
index 448b4c3c338a..fdf6b089844b 100644
--- a/pkgs/development/python-modules/pymatgen/default.nix
+++ b/pkgs/development/python-modules/pymatgen/default.nix
@@ -21,11 +21,11 @@
 
 buildPythonPackage rec {
   pname = "pymatgen";
-  version = "2020.12.3";
+  version = "2020.12.31";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "a7ae7aba87e88965c3e1490f5b9742c95e06150f2fc73da69647a9366dd88018";
+    sha256 = "5002490facd47c55d2dae42c35712e061c1f5d881180485c0543a899589856d6";
   };
 
   nativeBuildInputs = [ glibcLocales ];