diff --git a/cache.cabal b/cache.cabal
--- a/cache.cabal
+++ b/cache.cabal
@@ -1,5 +1,5 @@
 name:           cache
-version:        0.1.1.0
+version:        0.1.1.1
 synopsis:       An in-memory key/value store with expiration support
 homepage:       https://github.com/hverr/haskell-cache#readme
 license:        BSD3
diff --git a/src/Data/Cache.hs b/src/Data/Cache.hs
--- a/src/Data/Cache.hs
+++ b/src/Data/Cache.hs
@@ -225,7 +225,7 @@
 
 -- $use
 --
--- All operations are atomically executed in the IO monad. The
+-- All operations are automically executed in the IO monad. The
 -- underlying data structure is @Data.HashMap.Strict@.
 --
 -- First create a cache using 'newCache' and possibly a default
@@ -236,6 +236,10 @@
 -- only return a value when the item is in the cache and it is not
 -- expired. The 'lookup' function will automatically delete the
 -- item if it is expired, while 'lookup'' won't delete the item.
+--
+-- Note that items are __not purged automatically__ in the background when they
+-- expire. You have to manually call 'lookup' to purge a single item, or call
+-- 'purgeExpired' to purge all expired items.
 --
 -- > >>> c <- newCache Nothing :: IO (Cache String String)
 -- > >>> insert c "key" "value"