diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,15 @@
 
 ### Upcoming
 
+### v1.0.2.0
+
+*Revisions*
+
+* Bumped max version constraint of optparse-applicative. ([#20](https://github.com/hjwylde/werewolf/issues/20))
+
 ### v1.0.1.5
+
+*Revisions*
 
 * Bumped max version constraint of werewolf.
 
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -9,8 +9,10 @@
 A chat interface for playing [werewolf](https://github.com/hjwylde/werewolf) in
     [Slack](https://slack.com/).
 Werewolf is a well known social party game, commonly also called Mafia.
-See the [Wikipedia article](https://en.wikipedia.org/wiki/Mafia_(party_game)) for a rundown on it's
+See the [Wikipedia article](https://en.wikipedia.org/wiki/Mafia_(party_game)) for a rundown on its
     gameplay and history.
+
+![Werewolf for Slack](https://raw.githubusercontent.com/hjwylde/werewolf-slack/master/.readme/werewolf-for-slack.png)
 
 ### Game description
 
diff --git a/app/Werewolf/Slack/Options.hs b/app/Werewolf/Slack/Options.hs
--- a/app/Werewolf/Slack/Options.hs
+++ b/app/Werewolf/Slack/Options.hs
@@ -9,6 +9,8 @@
 Optparse utilities.
 -}
 
+{-# LANGUAGE CPP #-}
+
 module Werewolf.Slack.Options (
     -- * Options
     Options(..),
@@ -17,6 +19,9 @@
     werewolfSlackPrefs, werewolfSlackInfo, werewolfSlack,
 ) where
 
+#if MIN_VERSION_optparse_applicative(0,13,0)
+import Data.Monoid
+#endif
 import Data.Version (showVersion)
 
 import Network.Wai.Handler.Warp
@@ -26,16 +31,20 @@
 import qualified Werewolf.Slack.Version as This
 
 data Options = Options
-    { optDebug       :: Bool
-    , optPort        :: Port
-    , optToken       :: String
-    , optWebhookUrl  :: String
+    { optDebug      :: Bool
+    , optPort       :: Port
+    , optToken      :: String
+    , optWebhookUrl :: String
     } deriving (Eq, Show)
 
 -- | The default preferences.
 --   Limits the help output to 100 columns.
 werewolfSlackPrefs :: ParserPrefs
+#if MIN_VERSION_optparse_applicative(0,13,0)
+werewolfSlackPrefs = prefs $ columns 100 <> showHelpOnEmpty
+#else
 werewolfSlackPrefs = prefs $ columns 100
+#endif
 
 -- | An optparse parser of a werewolf-slack command.
 werewolfSlackInfo :: ParserInfo Options
diff --git a/werewolf-slack.cabal b/werewolf-slack.cabal
--- a/werewolf-slack.cabal
+++ b/werewolf-slack.cabal
@@ -1,5 +1,5 @@
 name:           werewolf-slack
-version:        1.0.1.5
+version:        1.0.2.0
 
 author:         Henry J. Wylde
 maintainer:     public@hjwylde.com
@@ -43,7 +43,7 @@
         http-client-tls == 0.2.*,
         http-types == 0.9.*,
         mtl == 2.2.*,
-        optparse-applicative == 0.12.*,
+        optparse-applicative >= 0.12 && < 0.14,
         process >= 1.2 && < 1.5,
         text == 1.2.*,
         wai == 3.2.*,