diff --git a/pkgs/development/tools/alloy/default.nix b/pkgs/development/tools/alloy/default.nix
index da247072b070..2c16f1f6f6cf 100644
--- a/pkgs/development/tools/alloy/default.nix
+++ b/pkgs/development/tools/alloy/default.nix
@@ -43,7 +43,6 @@ stdenv.mkDerivation rec {
   phases = [ "installPhase" ];
 
   installPhase = ''
-    jar=`basename ${src}`
     jar=$out/share/alloy/alloy${version}.jar
 
     install -Dm644 ${src} $jar