diff --git a/pkgs/applications/science/math/sage/sage-src.nix b/pkgs/applications/science/math/sage/sage-src.nix
index 2eb7f8100597..348adf5d5095 100644
--- a/pkgs/applications/science/math/sage/sage-src.nix
+++ b/pkgs/applications/science/math/sage/sage-src.nix
@@ -84,6 +84,12 @@ stdenv.mkDerivation rec {
   ];
 
   packageUpgradePatches = [
+    (fetchpatch {
+      name = "cypari2-1.2.1.patch";
+      url = "https://git.sagemath.org/sage.git/patch/?h=62fe6eb15111327d930336d4252d5b23cbb22ab9";
+      sha256 = "1xax7vvs8h4xip16xcsp47xdb6lig6f2r3pl8cksvlz8lhgbyxh2";
+    })
+
     # matplotlib 2.2.2 deprecated `normed` (replaced by `density`).
     # This patch only ignores the warning. It would be equally easy to fix it
     # (by replacing all mentions of `normed` by `density`), but its better to
diff --git a/pkgs/development/python-modules/cypari2/default.nix b/pkgs/development/python-modules/cypari2/default.nix
index fc3c311a5061..6df19e4c94be 100644
--- a/pkgs/development/python-modules/cypari2/default.nix
+++ b/pkgs/development/python-modules/cypari2/default.nix
@@ -7,16 +7,15 @@
 , gmp
 , cython
 , cysignals
-, six
 }:
 
 buildPythonPackage rec {
   pname = "cypari2";
-  version = "1.1.4"; # remove six dependency on upgrade to >1.1.4
+  version = "1.2.1";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "0n0mp8qmvvzmfaawg39d3mkyzf65q2zkz7bnqyk4sfjbz4xwc6mb";
+    sha256 = "0v2kikwf0advq8j76nwzhlacwj1yys9cvajm4fqgmasjdsnf1q4k";
   };
 
   # This differs slightly from the default python installPhase in that it pip-installs
@@ -39,7 +38,6 @@ buildPythonPackage rec {
   propagatedBuildInputs = [
     cysignals
     cython
-    six # after 1.1.4: will not be needed
   ];
 
   checkPhase = ''