diff --git a/src/Pure/Admin/build_zipperposition.scala b/src/Pure/Admin/build_zipperposition.scala
--- a/src/Pure/Admin/build_zipperposition.scala
+++ b/src/Pure/Admin/build_zipperposition.scala
@@ -1,117 +1,118 @@
 /*  Title:      Pure/Admin/build_zipperposition.scala
     Author:     Makarius
 
 Build Isabelle Zipperposition component from OPAM repository.
 */
 
 package isabelle
 
 
 object Build_Zipperposition
 {
   val default_version = "1.6"
 
 
   /* build Zipperposition */
 
   def build_zipperposition(
     version: String = default_version,
     verbose: Boolean = false,
     progress: Progress = new Progress,
     target_dir: Path = Path.current)
   {
     Isabelle_System.with_tmp_dir("build")(build_dir =>
     {
       /* component */
 
       val component_name = "zipperposition-" + version
       val component_dir = Isabelle_System.new_directory(target_dir + Path.basic(component_name))
       progress.echo("Component " + component_dir)
 
 
       /* platform */
 
       val platform_name =
         proper_string(Isabelle_System.getenv("ISABELLE_PLATFORM64")) getOrElse
         error("No 64bit platform")
 
       val platform_dir = Isabelle_System.make_directory(component_dir + Path.basic(platform_name))
 
 
       /* build */
 
       progress.echo("OCaml/OPAM setup ...")
       progress.bash("isabelle ocaml_setup", echo = verbose).check
 
       progress.echo("Building Zipperposition for " + platform_name + " ...")
       progress.bash(cwd = build_dir.file, echo = verbose,
         script = "isabelle_opam install -y --destdir=" + File.bash_path(build_dir) +
           " zipperposition=" + Bash.string(version)).check
 
 
       /* install */
 
       File.copy(build_dir + Path.explode("doc/zipperposition/LICENSE"), component_dir)
 
-      val exe_path = Path.basic("zipperposition").platform_exe
-      File.copy(build_dir + Path.basic("bin") + exe_path, platform_dir)
+      val prg_path = Path.basic("zipperposition")
+      val exe_path = prg_path.platform_exe
+      File.copy(build_dir + Path.basic("bin") + prg_path, platform_dir + exe_path)
 
       Executable.libraries_closure(
         platform_dir + exe_path, filter = Set("libgmp"), patchelf = true)
 
 
       /* settings */
 
       val etc_dir = Isabelle_System.make_directory(component_dir + Path.basic("etc"))
       File.write(etc_dir + Path.basic("settings"),
         """# -*- shell-script -*- :mode=shellscript:
 
 ISABELLE_ZIPPERPOSITION="$COMPONENT/$ISABELLE_PLATFORM64/zipperposition"
 """)
 
 
       /* README */
 
       File.write(component_dir + Path.basic("README"),
 """This is Zipperposition """ + version + """ from the OCaml/OPAM repository.
 
 
         Makarius
         """ + Date.Format.date(Date.now()) + "\n")
     })
 }
 
 
   /* Isabelle tool wrapper */
 
   val isabelle_tool =
     Isabelle_Tool("build_zipperposition", "build prover component from OPAM repository",
     args =>
     {
       var target_dir = Path.current
       var version = default_version
       var verbose = false
 
       val getopts = Getopts("""
 Usage: isabelle build_zipperposition [OPTIONS]
 
   Options are:
     -D DIR       target directory (default ".")
     -V VERSION   version (default: """" + default_version + """")
     -v           verbose
 
   Build prover component from OPAM repository.
 """,
         "D:" -> (arg => target_dir = Path.explode(arg)),
         "V:" -> (arg => version = arg),
         "v" -> (_ => verbose = true))
 
       val more_args = getopts(args)
       if (more_args.nonEmpty) getopts.usage()
 
       val progress = new Console_Progress()
 
       build_zipperposition(version = version, verbose = verbose, progress = progress,
         target_dir = target_dir)
     })
 }