diff --git a/pkgs/applications/virtualization/virtualbox/guest-additions/default.nix b/pkgs/applications/virtualization/virtualbox/guest-additions/default.nix
index f0af4411d9c..52c1f46fdae 100644
--- a/pkgs/applications/virtualization/virtualbox/guest-additions/default.nix
+++ b/pkgs/applications/virtualization/virtualbox/guest-additions/default.nix
@@ -17,22 +17,25 @@ stdenv.mkDerivation {
   '';
   
   buildCommand = ''
-    ${if stdenv.system == "i686-linux" then ''
-        isoinfo -J -i $src -x /VBoxLinuxAdditions-x86.run > ./VBoxLinuxAdditions-x86.run
-        chmod 755 ./VBoxLinuxAdditions-x86.run
-        ./VBoxLinuxAdditions-x86.run --noexec --keep
-      ''
-      else if stdenv.system == "x86_64-linux" then ''
-        isoinfo -J -i $src -x /VBoxLinuxAdditions-amd64.run > ./VBoxLinuxAdditions-amd64.run
-        chmod 755 ./VBoxLinuxAdditions-amd64.run
-	./VBoxLinuxAdditions-amd64.run --noexec --keep
+    ${if stdenv.system == "i686-linux" || stdenv.system == "x86_64-linux" then ''
+        isoinfo -J -i $src -x /VBoxLinuxAdditions.run > ./VBoxLinuxAdditions.run
+        chmod 755 ./VBoxLinuxAdditions.run
+	./VBoxLinuxAdditions.run --noexec --keep
       ''
       else throw ("Architecture: "+stdenv.system+" not supported for VirtualBox guest additions")
     }
     
     # Unpack files
     cd install
-    tar xfvj VBoxGuestAdditions.tar.bz2
+    ${if stdenv.system == "i686-linux" then ''
+        tar xfvj VBoxGuestAdditions-x86.tar.bz2
+      ''
+      else if stdenv.system == "x86_64-linux" then ''
+        tar xfvj VBoxGuestAdditions-amd64.tar.bz2
+      ''
+      else throw ("Architecture: "+stdenv.system+" not supported for VirtualBox guest additions")
+    }
+
     
     # Build kernel modules    
     cd src        
@@ -41,9 +44,11 @@ stdenv.mkDerivation {
     do
 	cd $i
 	sed -i -e "s/depmod/echo/g" Makefile
+	sed -i -e "s/depmod/echo/g" */Makefile
 	make
 	cd ..
     done
+
     cd ..
     
     # Change the interpreter for various binaries