diff --git a/var/spack/repos/builtin/packages/llvm/package.py b/var/spack/repos/builtin/packages/llvm/package.py
index 057297737cc..26eb9087add 100644
--- a/var/spack/repos/builtin/packages/llvm/package.py
+++ b/var/spack/repos/builtin/packages/llvm/package.py
@@ -374,5 +374,4 @@ def install(self, spec, prefix):
             cmake(*cmake_args)
             make()
             make("install")
-            cp = which('cp')
-            cp('-a', 'bin/', prefix)
+            install_tree("bin", prefix.bin)