diff --git a/pkgs/development/libraries/java/saxon/default.nix b/pkgs/development/libraries/java/saxon/default.nix
index f0e34478e01e..e7d5cd8798a9 100644
--- a/pkgs/development/libraries/java/saxon/default.nix
+++ b/pkgs/development/libraries/java/saxon/default.nix
@@ -37,8 +37,9 @@ let
         inherit pname version src;
 
         nativeBuildInputs = [ unzip ];
+        dontUnpack = true;
 
-        buildCommand = ''
+        installPhase = ''
           unzip $src -d $out
           mkdir -p $out/bin $out/share $out/share/java
           cp -s "$out"/*.jar "$out/share/java/"  # */