diff --git a/Graphics/PDF/Draw.hs b/Graphics/PDF/Draw.hs
index eff9001..15c050e 100644
--- a/Graphics/PDF/Draw.hs
+++ b/Graphics/PDF/Draw.hs
@@ -95,6 +95,7 @@ import qualified Data.ByteString.Lazy as B
 import Control.Monad.ST
 import Data.STRef
 
+import Control.Monad.Fail
 import Control.Monad.Writer.Class
 import Control.Monad.Reader.Class
 import Control.Monad.State
@@ -212,6 +213,9 @@ instance Functor Draw where
 
 instance MonadPath Draw
 
+instance MonadFail Draw where
+  fail err = error "Draw monad failed"
+
 readDrawST :: (forall s. DrawTuple s -> STRef s a) -> Draw a
 readDrawST   f   = Draw $ \env -> readSTRef   (f env) 
 
diff --git a/HPDF.cabal b/HPDF.cabal
index 752fe9c..5f54cf2 100644
--- a/HPDF.cabal
+++ b/HPDF.cabal
@@ -17,7 +17,7 @@ extra-source-files:
   Test/Makefile
   Test/Penrose.hs
   Test/test.hs
-  README.txt
+  README.md
   NEWS.txt
   TODO.txt
   changelog
diff --git a/stack.yaml b/stack.yaml
index 655499c..b86861c 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,7 +1,7 @@
 # For more information, see: https://github.com/commercialhaskell/stack/blob/release/doc/yaml_configuration.md
 
 # Specifies the GHC version and set of packages available (e.g., lts-3.5, nightly-2015-09-21, ghc-7.10.2)
-resolver: lts-6.14
+resolver: lts-14.13
 
 # Local packages, usually specified by relative directory name
 packages: