diff --git a/ListLike.cabal b/ListLike.cabal
--- a/ListLike.cabal
+++ b/ListLike.cabal
@@ -1,5 +1,5 @@
 Name: ListLike
-Version: 4.7.7
+Version: 4.7.8
 License: BSD3
 Maintainer: David Fox <dsf@seereason.com>, Andreas Abel
 Author: John Goerzen
@@ -69,7 +69,7 @@
                 ,bytestring >= 0.9.1 && < 0.12
                 ,array      >= 0.3   && < 0.6
                 ,text       >= 0.11  && < 1.3  || == 2.0.*
-                ,vector     >= 0.5   && < 0.13
+                ,vector     >= 0.5   && < 0.14
                 ,dlist      >= 0.7   && < 1.1
                 ,fmlist     >= 0.8   && < 0.10
                 ,utf8-string >= 0.3.1 && < 1.1
diff --git a/src/Data/ListLike/Base.hs b/src/Data/ListLike/Base.hs
--- a/src/Data/ListLike/Base.hs
+++ b/src/Data/ListLike/Base.hs
@@ -513,10 +513,11 @@
     {- | Like 'insert', but with a custom comparison function -}
     insertBy :: (item -> item -> Ordering) -> item ->
                 full -> full
-    insertBy cmp x ys
-        | null ys = singleton x
-        | otherwise = case cmp x (head ys) of
-                        GT -> cons (head ys) (insertBy cmp x (tail ys))
+    insertBy cmp x ys =
+        case uncons ys of
+            Nothing -> singleton x
+            Just (ys_head,ys_tail) -> case cmp x ys_head of
+                        GT -> cons ys_head (insertBy cmp x ys_tail)
                         _ ->  cons x ys
 
     ------------------------------ Generic Operations
diff --git a/src/Data/ListLike/DList.hs b/src/Data/ListLike/DList.hs
--- a/src/Data/ListLike/DList.hs
+++ b/src/Data/ListLike/DList.hs
@@ -6,6 +6,8 @@
 
 module Data.ListLike.DList () where
 
+import qualified Prelude
+
 import Data.ListLike.Base
 import Data.ListLike.FoldableLL
 import Data.ListLike.String
@@ -21,6 +23,7 @@
 import Control.Category
 import Data.Char (Char)
 
+
 instance FoldableLL (DList a) a where
   foldl = F.foldl
   foldr = D.foldr
@@ -56,6 +59,11 @@
   --toList = D.toList
   --fromList = D.fromList
   replicate = D.replicate
+  uncons xs = case xs of
+    D.Nil -> Prelude.Nothing
+    D.Cons d_head l_tail -> Prelude.Just (d_head,fromList l_tail)
+    _ -> Prelude.error "Workaround for missing COMPLETE pragma on dlist patterns"
+
 
 instance StringLike (DList Char) where
   toString = D.toList