diff --git a/pkgs/build-support/mkshell/default.nix b/pkgs/build-support/mkshell/default.nix
index 39b02a47141a..3517e949f67a 100644
--- a/pkgs/build-support/mkshell/default.nix
+++ b/pkgs/build-support/mkshell/default.nix
@@ -53,4 +53,6 @@ stdenv.mkDerivation ({
       export;
     } >> "$out"
   '';
+
+  preferLocalBuild = true;
 } // rest)