diff --git a/release.nix b/release.nix
index c0fc485..49d6ee2 100644
--- a/release.nix
+++ b/release.nix
@@ -132,14 +132,16 @@ in let
     pkgs =
       builtins.listToAttrs
         ( builtins.map ( name: { inherit name; value = pkgs.${name}; } )
-            ( builtins.attrNames ( let self = import ./pkgs/all-packages.nix self { } self; in self ) ) );
+          ( builtins.filter ( name: builtins.isAttrs pkgs.${name} && pkgs.${name}.type or "" == "derivation" )
+            ( builtins.attrNames ( let self = import ./pkgs/all-packages.nix self { } self; in self ) ) ) );
 
     # temporary - Attribute set of overlayed pkgs.
     #
     temporary =
       builtins.listToAttrs
-      ( map ( name: { inherit name; value = pkgs.${name}; } )
-          ( builtins.attrNames ( let self = import ./temporary/all-temporary.nix self { } self; in self ) ) );
+        ( map ( name: { inherit name; value = pkgs.${name}; } )
+          ( builtins.filter ( name: builtins.isAttrs pkgs.${name} && pkgs.${name}.type or "" == "derivation" )
+            ( builtins.attrNames ( let self = import ./temporary/all-temporary.nix self { } self; in self ) ) ) );
   };
 
 in jobs