2 files changed, 8 insertions, 7 deletions
diff --git a/src/Reaktor/Plugins/Register.hs b/src/Reaktor/Plugins/Register.hs
index 979e4ba..dcd130e 100644
--- a/src/Reaktor/Plugins/Register.hs
+++ b/src/Reaktor/Plugins/Register.hs
@@ -6,6 +6,7 @@ module Reaktor.Plugins.Register where
 
 import Blessings
 import Data.Aeson
+import Data.Aeson.Types (typeMismatch)
 import qualified Data.Text as T
 import qualified Data.Text.IO as T
 import Prelude.Extended
@@ -23,7 +24,7 @@ instance FromJSON ConfigNickServ where
       ConfigNickServ
         <$> v .: "passFile"
         <*> v .:? "prefix" .!= "NickServ!NickServ@services."
-    _ -> undefined
+    invalid -> typeMismatch "ConfigNickServ" invalid
 
 data Config = Config
     { cNick :: Maybe Text
@@ -43,7 +44,7 @@ instance FromJSON Config where
       cChannels <- v .:? "channels" .!= []
       cNickServ <- v .:? "NickServ" .!= cNickServ def
       pure Config{..}
-    _ -> undefined
+    invalid -> typeMismatch "Config" invalid
 
 new :: Config -> Actions -> IO (Message -> IO ())
 new Config{..} Actions{..} = do
diff --git a/src/Reaktor/Plugins/System/Internal.hs b/src/Reaktor/Plugins/System/Internal.hs
index 78c8802..e4356df 100644
--- a/src/Reaktor/Plugins/System/Internal.hs
+++ b/src/Reaktor/Plugins/System/Internal.hs
@@ -4,6 +4,7 @@ module Reaktor.Plugins.System.Internal where
 
 import Prelude.Extended
 import Data.Aeson
+import Data.Aeson.Types (typeMismatch)
 import Reaktor ()
 import qualified Reaktor.IRC as IRC
 import Text.Regex.PCRE.Light (Regex)
@@ -27,7 +28,7 @@ instance FromJSON Activate where
       String "always" -> pure Always
       String "match" -> pure Match
       String "query" -> pure Query
-      _ -> undefined
+      invalid -> typeMismatch "Activate" invalid
 
 data Config = Config
     { cWorkDir :: Maybe FilePath
@@ -44,7 +45,7 @@ instance FromJSON Config where
         Config
           <$> v .:? "workdir"
           <*> v .:? "hooks" .!= mempty
-      _ -> undefined
+      invalid -> typeMismatch "Config" invalid
 
 data Hook = Hook
     { hActivate :: Activate
@@ -68,7 +69,7 @@ instance FromJSON Hook where
           <*> v .:? "workdir"
           <*> v .:? "commands" .!= mempty
           <*> (fmap (*1000000) <$> v .:? "timeoutSec" .!= Just 10)
-      _ -> undefined
+      invalid -> typeMismatch "Hook" invalid
 
 
 data SystemCommand = SystemCommand
@@ -85,5 +86,4 @@ instance FromJSON SystemCommand where
           <$> v .: "filename"
           <*> v .:? "workdir"
           <*> v .:? "env"
-      _ -> undefined
-
+      invalid -> typeMismatch "SystemCommand" invalid