diff --git a/pkgs/os-specific/linux/bbswitch/default.nix b/pkgs/os-specific/linux/bbswitch/default.nix
index 502d24d32d8b..a8f8a9d33ef3 100644
--- a/pkgs/os-specific/linux/bbswitch/default.nix
+++ b/pkgs/os-specific/linux/bbswitch/default.nix
@@ -1,9 +1,8 @@
 { stdenv, fetchurl, kernel }:
 
 let
-
-  version = "0.4.1";
-  name = "bbswitch-${version}-${kernel.version}";
+  baseName = "bbswitch-0.4.1";
+  name = "${baseName}-${kernel.version}";
 
 in
 
@@ -11,7 +10,7 @@ stdenv.mkDerivation {
   inherit name;
 
   src = fetchurl {
-    url = "http://github.com/downloads/Bumblebee-Project/bbswitch/${name}.tar.gz";
+    url = "http://github.com/downloads/Bumblebee-Project/bbswitch/${baseName}.tar.gz";
     sha256 = "d579c6efc5f6482f0cf0b2c1b1f1a127413218cdffdc8f2d5a946c11909bda23";
   };
 
diff --git a/pkgs/os-specific/linux/frandom/default.nix b/pkgs/os-specific/linux/frandom/default.nix
index fb2c50a778d5..7894e86ded98 100644
--- a/pkgs/os-specific/linux/frandom/default.nix
+++ b/pkgs/os-specific/linux/frandom/default.nix
@@ -1,10 +1,13 @@
 { stdenv, fetchurl, kernel }:
 
+let baseName = "frandom-1.1";
+in
+
 stdenv.mkDerivation rec {
-  name = "frandom-1.1-${kernel.version}";
+  name = "${baseName}-${kernel.version}";
 
   src = fetchurl {
-    url = "http://sourceforge.net/projects/frandom/files/${name}.tar.gz";
+    url = "http://sourceforge.net/projects/frandom/files/${baseName}.tar.gz";
     sha256 = "15rgyk4hfawqg7z1spk2xlk1nn6rcdls8gdhc70f91shrc9pvlls";
   };