diff --git a/pkgs/top-level/config.nix b/pkgs/top-level/config.nix
index 526dd4182702..3f7ad3b20f29 100644
--- a/pkgs/top-level/config.nix
+++ b/pkgs/top-level/config.nix
@@ -471,6 +471,22 @@ let
       '';
     };
 
+    packageOverrides = mkOption {
+      type = types.functionTo types.attrs;
+      default = pkgs: { };
+      description = ''
+        A function to replace or add packages in `pkgs` expects an attrset to be returned when called.
+      '';
+    };
+
+    perlPackageOverrides = mkOption {
+      type = types.functionTo types.attrs;
+      default = pkgs: { };
+      description = ''
+        The same as `packageOverrides` but for packages in the perl package set.
+      '';
+    };
+
     problems = (import ../stdenv/generic/problems.nix { inherit lib; }).configOptions;
   };