1 files changed, 5 insertions, 3 deletions

diff --git a/lib/Postdelay/TimeSpec/Utils.hs b/lib/Postdelay/TimeSpec/Utils.hs
index e4ba732..85ac299 100644
--- a/lib/Postdelay/TimeSpec/Utils.hs
+++ b/lib/Postdelay/TimeSpec/Utils.hs
@@ -7,8 +7,10 @@ import Control.Monad
 import Control.Lens
 
 import Data.Time
+import Data.Time.Lens
 import Data.Time.Zones
 
+import Data.Functor
 import Data.AdditiveGroup
 
 import Text.Megaparsec
@@ -30,6 +32,6 @@ signed = (<*>) (lexeme sign)
 optSigned = (<*>) (option id $ lexeme sign)
 
 sign :: (StringParser s m, AdditiveGroup n) => m (n -> n)
-sign = choice [ id <$ char '+'
-              , negateV <$ char '-'
-              ]
+sign = label "sign" $ choice [ char '+' $> id
+                             , char '-' $> negateV
+                             ]