diff --git a/pkgs/development/libraries/boost/1.40.0.nix b/pkgs/development/libraries/boost/1.40.0.nix
index e67af56a362..855c20f9d9f 100644
--- a/pkgs/development/libraries/boost/1.40.0.nix
+++ b/pkgs/development/libraries/boost/1.40.0.nix
@@ -25,7 +25,7 @@ let
   finalLayout = if ((enableRelease && enableDebug) ||
     (enableSingleThreaded && enableMultiThreaded) ||
     (enableShared && enableStatic)) then
-    "system" else "tagged";
+    "tagged" else "system";
 
 in