diff --git a/pkgs/overlays/unstable-from-source.nix b/pkgs/overlays/unstable-from-source.nix
index bca6b9f..dbd0728 100644
--- a/pkgs/overlays/unstable-from-source.nix
+++ b/pkgs/overlays/unstable-from-source.nix
@@ -15,26 +15,26 @@ let
     "parsed"
   ];
 
-  unstablePkgsForNixpkgs = nixpkgs: import unstableSource {
+  unstablePkgs = import unstableSource {
     # localSystem -> pkgs.stdenv.buildPlatform
-    localSystem = sanitizePlatform nixpkgs.stdenv.buildPlatform;
+    localSystem = sanitizePlatform self.stdenv.buildPlatform;
     # crossSystem -> pkgs.stdenv.hostPlatform or pkgs.stdenv.targetPlatform ??
     # passing below
     # config -> pkgs.config
-    config = nixpkgs.config;
+    config = self.config;
     # overlays -> partial of pkgs.overlays
-    overlays = nixpkgs.overlays;
+    overlays = self.overlays;
     # crossOverlays -> partial of pkgs.overlays
     # crossOverlays are merged to overlays, not sure what issues that might raise.
     # ignoring.
   } // self.lib.optionalAttrs (
-    self.lib.systems.equals nixpkgs.stdenv.buildPlatform nixpkgs.stdenv.hostPlatform
+    self.lib.systems.equals self.stdenv.buildPlatform self.stdenv.hostPlatform
   ) {
     # workaround for some odd structured packages that changes behaviour
     # when crossSystem is passed.
-    crossSystem = sanitizePlatform nixpkgs.stdenv.hostPlatform;
+    crossSystem = sanitizePlatform self.stdenv.hostPlatform;
   };
 in
 {
-  "${attributeName}" = if useUnstable then unstablePkgsForNixpkgs self else self;
+  "${attributeName}" = if useUnstable then unstablePkgs else self;
 }