diff --git a/pkgs/development/python-modules/altair/default.nix b/pkgs/development/python-modules/altair/default.nix
index 6e686d9fc907..0d5dd95c8333 100644
--- a/pkgs/development/python-modules/altair/default.nix
+++ b/pkgs/development/python-modules/altair/default.nix
@@ -18,12 +18,12 @@
 
 buildPythonPackage rec {
   pname = "altair";
-  version = "4.1.0";
+  version = "4.2.0";
   disabled = isPy27;
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "0c99q5dy6f275yg1f137ird08wmwc1z8wmvjickkf2mvyka31p9y";
+    sha256 = "d87d9372e63b48cd96b2a6415f0cf9457f50162ab79dc7a31cd7e024dd840026";
   };
 
   propagatedBuildInputs = [