diff --git a/pkgs/applications/science/math/yacas/default.nix b/pkgs/applications/science/math/yacas/default.nix
index c19d8f0fbc17..06aab669df5a 100644
--- a/pkgs/applications/science/math/yacas/default.nix
+++ b/pkgs/applications/science/math/yacas/default.nix
@@ -5,13 +5,13 @@
 
 stdenv.mkDerivation rec {
   pname = "yacas";
-  version = "1.8.0";
+  version = "1.9.1";
 
   src = fetchFromGitHub {
     owner = "grzegorzmazur";
     repo = "yacas";
     rev = "v${version}";
-    sha256 = "0fwd98dwq6g0md3yhgyl30i377593b8rw6gsvffzvs11g3aqf1ga";
+    sha256 = "0dqgqvsb6ggr8jb3ngf0jwfkn6xwj2knhmvqyzx3amc74yd3ckqx";
   };
 
   hardeningDisable = [ "format" ];