diff --git a/pkgs/os-specific/linux/kernel/linux-2.6.31.nix b/pkgs/os-specific/linux/kernel/linux-2.6.31.nix
index 33eed2541eff..cbeb613f9c8e 100644
--- a/pkgs/os-specific/linux/kernel/linux-2.6.31.nix
+++ b/pkgs/os-specific/linux/kernel/linux-2.6.31.nix
@@ -29,7 +29,7 @@ import ./generic.nix (
           sed -re "1i$1=m" -i .config
         }
         setOptionYes () {
-          sed -re 's/^# )'"$1"') is not set/\1=y/' -i .config
+          sed -re 's/^# ('"$1"') is not set/\1=y/' -i .config
           sed -re "1i$1=y" -i .config
         }
         
diff --git a/pkgs/os-specific/linux/zen-kernel/2.6.31-zen0.nix b/pkgs/os-specific/linux/zen-kernel/2.6.31-zen0.nix
index 606a3280cb2e..360226487217 100644
--- a/pkgs/os-specific/linux/zen-kernel/2.6.31-zen0.nix
+++ b/pkgs/os-specific/linux/zen-kernel/2.6.31-zen0.nix
@@ -30,7 +30,7 @@ in
       sed -re "1i$1=m" -i .config
     }
     setOptionYes () {
-      sed -re 's/^# )'"$1"') is not set/\1=y/' -i .config
+      sed -re 's/^# ('"$1"') is not set/\1=y/' -i .config
       sed -re "1i$1=y" -i .config
     }