diff --git a/aeson-prefix.cabal b/aeson-prefix.cabal
--- a/aeson-prefix.cabal
+++ b/aeson-prefix.cabal
@@ -1,5 +1,5 @@
 name:                aeson-prefix
-version:             0.1.0.1
+version:             0.1.0.2
 synopsis:            Hiearchical prefixing for aeson
 description:         Please see README.md
 homepage:            https://github.com/j1r1k/aeson-prefix#readme
diff --git a/src/Data/Aeson/Prefix.hs b/src/Data/Aeson/Prefix.hs
--- a/src/Data/Aeson/Prefix.hs
+++ b/src/Data/Aeson/Prefix.hs
@@ -31,7 +31,8 @@
 --
 -- @{ "a": 1 }@ results in @{ "prefix.a": 1 }@
 --
--- * This affects only keys in top level object. If array is top level, it doesn't take effect
+-- * This affects only keys in top level object. 
+-- * If array is top level, it doesn't take effect unless you set 'optionPreservePrefix' to 'True'
 --
 -- === With 'optionSeparator' set to "~"
 --