diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,11 @@
 
+50200.14.1
+==========
+
+Bug fixes:
+ * Fixed an issue where some builds would crash right after startup with
+   a missing "mappend" exception.
+
 50200.14.0
 ==========
 
diff --git a/matterhorn.cabal b/matterhorn.cabal
--- a/matterhorn.cabal
+++ b/matterhorn.cabal
@@ -1,5 +1,5 @@
 name:                matterhorn
-version:             50200.14.0
+version:             50200.14.1
 synopsis:            Terminal client for the Mattermost chat system
 description:         This is a terminal client for the Mattermost chat
                      system. Please see the README for a list of
diff --git a/src/Matterhorn/Types/Channels.hs b/src/Matterhorn/Types/Channels.hs
--- a/src/Matterhorn/Types/Channels.hs
+++ b/src/Matterhorn/Types/Channels.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE DeriveFoldable #-}
@@ -341,6 +342,9 @@
 
 instance Monoid (AllMyChannels ClientChannel) where
     mempty = noChannels
+#if !MIN_VERSION_base(4,11,0)
+    mappend = (<>)
+#endif
 
 getDmChannelFor :: UserId -> ClientChannels -> Maybe ChannelId
 getDmChannelFor uId cs = cs^.userChannelMap.at uId