diff --git a/pkgs/development/interpreters/pypy/default.nix b/pkgs/development/interpreters/pypy/default.nix
index 143bab575347..a4eb7439b0d5 100644
--- a/pkgs/development/interpreters/pypy/default.nix
+++ b/pkgs/development/interpreters/pypy/default.nix
@@ -114,6 +114,7 @@ let
       isPypy = true;
       buildEnv = callPackage ../python/wrapper.nix { python = self; };
       interpreter = "${self}/bin/${executable}";
+      sitePackages = "lib/${libPrefix}/site-packages";
     };
 
     enableParallelBuilding = true;  # almost no parallelization without STM