diff --git a/pkgs/servers/x11/xorg/overrides.nix b/pkgs/servers/x11/xorg/overrides.nix
index 7bd179067cd0..b3d13c9c2589 100644
--- a/pkgs/servers/x11/xorg/overrides.nix
+++ b/pkgs/servers/x11/xorg/overrides.nix
@@ -440,4 +440,8 @@ in
     configureFlags = "--with-cpp=${args.mcpp}/bin/mcpp";
   };
 
+  sessreg = attrs: attrs // {
+    preBuild = "sed -i 's|gcc -E|gcc -E -P|' man/Makefile";
+  };
+
 }