diff --git a/pkgs/servers/x11/xorg/default.nix b/pkgs/servers/x11/xorg/default.nix
index ca9483ab0c20..cc457791e893 100644
--- a/pkgs/servers/x11/xorg/default.nix
+++ b/pkgs/servers/x11/xorg/default.nix
@@ -1438,11 +1438,11 @@ self: with self; {
   # THIS IS A GENERATED FILE.  DO NOT EDIT!
   libXmu = callPackage ({ stdenv, pkg-config, fetchurl, libX11, libXext, xorgproto, libXt, testers }: stdenv.mkDerivation (finalAttrs: {
     pname = "libXmu";
-    version = "1.1.4";
+    version = "1.2.1";
     builder = ./builder.sh;
     src = fetchurl {
-      url = "mirror://xorg/individual/lib/libXmu-1.1.4.tar.xz";
-      sha256 = "0i42fng5gizablqziib25ipcwm5830jprl955ibq54rykjmy6391";
+      url = "mirror://xorg/individual/lib/libXmu-1.2.1.tar.xz";
+      sha256 = "1cp82iz7yki63iykvb3alwy4nwy01k2axi5rqpyfafca4j9pgcpw";
     };
     hardeningDisable = [ "bindnow" "relro" ];
     strictDeps = true;
diff --git a/pkgs/servers/x11/xorg/tarballs.list b/pkgs/servers/x11/xorg/tarballs.list
index ce0d9105bea5..716043aa0593 100644
--- a/pkgs/servers/x11/xorg/tarballs.list
+++ b/pkgs/servers/x11/xorg/tarballs.list
@@ -190,7 +190,7 @@ mirror://xorg/individual/lib/libXft-2.3.8.tar.xz
 mirror://xorg/individual/lib/libXi-1.8.1.tar.xz
 mirror://xorg/individual/lib/libXinerama-1.1.5.tar.xz
 mirror://xorg/individual/lib/libxkbfile-1.1.3.tar.xz
-mirror://xorg/individual/lib/libXmu-1.1.4.tar.xz
+mirror://xorg/individual/lib/libXmu-1.2.1.tar.xz
 mirror://xorg/individual/lib/libXp-1.0.4.tar.xz
 mirror://xorg/individual/lib/libXpm-3.5.17.tar.xz
 mirror://xorg/individual/lib/libXpresent-1.0.1.tar.xz