diff --git a/pkgs/games/xmage/default.nix b/pkgs/games/xmage/default.nix
index 783a9f5ea469..b6aa8e22afd2 100644
--- a/pkgs/games/xmage/default.nix
+++ b/pkgs/games/xmage/default.nix
@@ -21,12 +21,14 @@ stdenv.mkDerivation (finalAttrs: {
     ${unzip}/bin/unzip $src
   '';
 
-  installPhase = ''
+  installPhase = let
+    strVersion = lib.substring 0 6 finalAttrs.version;
+  in ''
     mkdir -p $out/bin
     cp -rv ./* $out
 
     cat << EOS > $out/bin/xmage
-    exec ${jdk8}/bin/java -Xms256m -Xmx512m -XX:MaxPermSize=384m -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -jar $out/mage-client/lib/mage-client-1.4.50.jar
+    exec ${jdk8}/bin/java -Xms256m -Xmx512m -XX:MaxPermSize=384m -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -jar $out/mage-client/lib/mage-client-${strVersion}.jar
     EOS
 
     chmod +x $out/bin/xmage