diff --git a/Data/SortedList.hs b/Data/SortedList.hs
--- a/Data/SortedList.hs
+++ b/Data/SortedList.hs
@@ -26,6 +26,9 @@
   , splitAt
   , filter
     -- * Queries
+#if !MIN_VERSION_base(4,8,0)
+  , null
+#endif
   , elemOrd
     -- * Others
   , map
@@ -41,18 +44,18 @@
 #endif
     )
 import qualified Data.List as List
+#if MIN_VERSION_base(4,5,0)
 import Data.Monoid ((<>))
+#endif
 import Data.Foldable (Foldable (..))
--- GHC 7.8.3 compatibility
 #if !MIN_VERSION_base(4,8,0)
 import Data.Monoid (Monoid (..))
-import Data.Foldable (Foldable, foldr)
 #endif
 --
 
 -- | Type of sorted lists. Any (non-bottom) value of this type
 --   is a sorted list.
-newtype SortedList a = SortedList [a]
+newtype SortedList a = SortedList [a] deriving (Eq, Ord)
 
 instance Show a => Show (SortedList a) where
   show = show . fromSortedList
@@ -122,7 +125,11 @@
 
 -- | /O(n)/. Insert a new element in a sorted list.
 insert :: Ord a => a -> SortedList a -> SortedList a
+#if MIN_VERSION_base(4,5,0)
 insert x xs = singleton x <> xs
+#else
+insert x xs = mappend (singleton x) xs
+#endif
 
 -- | Extract the prefix with the given length from a sorted list.
 take :: Int -> SortedList a -> SortedList a
diff --git a/sorted-list.cabal b/sorted-list.cabal
--- a/sorted-list.cabal
+++ b/sorted-list.cabal
@@ -1,5 +1,5 @@
 name:                sorted-list
-version:             0.1.2.1
+version:             0.1.3.0
 synopsis:            Type-enforced sorted lists and related functions.
 description:         Type-enforced sorted lists and related functions.
                      .