diff --git a/pkgs/games/fsg/default.nix b/pkgs/games/fsg/default.nix
index 7a9dc1105408..a4579ad2ae36 100644
--- a/pkgs/games/fsg/default.nix
+++ b/pkgs/games/fsg/default.nix
@@ -34,6 +34,7 @@ stdenv.mkDerivation {
     sed -e '
       s@currentProbIndex != 100@0@;
     ' -i MainFrame.cpp
+    sed -re '/ctrans_prob/s/energy\[center][+]energy\[other]/(int)(fmin(energy[center]+energy[other],99))/g' -i Canvas.cpp
   '';
 
   installPhase = ''