diff --git a/Propellor/Property/SiteSpecific/JoeySites.hs b/Propellor/Property/SiteSpecific/JoeySites.hs
index 587b9c2..06865c4 100644
--- a/Propellor/Property/SiteSpecific/JoeySites.hs
+++ b/Propellor/Property/SiteSpecific/JoeySites.hs
@@ -119,7 +119,8 @@ obnamLowMem :: Property
 obnamLowMem = combineProperties "obnam tuned for low memory use"
 	[ Obnam.latestVersion
 	, "/etc/obnam.conf" `File.containsLines`
-		[ "# Suggested by liw to keep Obnam memory consumption down (at some speed cost)."
+		[ "[config]"
+		, "# Suggested by liw to keep Obnam memory consumption down (at some speed cost)."
 		, "upload-queue-size = 128"
 		, "lru-size = 128"
 		]