diff --git a/exec/period.hs b/exec/period.hs
--- a/exec/period.hs
+++ b/exec/period.hs
@@ -27,7 +27,7 @@
     help "Field separator, by default '-' as in 'yyyy-mm-dd'") <*>
   option (T.pack <$> str) (
     short 'd' <> long "date-sep" <> value "," <>
-    help "Field separator, by default ',' as in 'yyyy-mm-dd,yyyy-mm-dd'")
+    help "Start and end separator, by default ',' as in 'yyyy-mm-dd,yyyy-mm-dd'")
 
 
 mkCommand :: String -> String -> Parser Command -> Mod CommandFields Command
diff --git a/period.cabal b/period.cabal
--- a/period.cabal
+++ b/period.cabal
@@ -1,5 +1,5 @@
 name:                period
-version:             0.1.0.3
+version:             0.1.0.4
 synopsis:            Parse and format date periods, collapse and expand their text representations.
 -- description:         
 homepage:            https://github.com/w3rs/period
@@ -16,7 +16,7 @@
 library
   exposed-modules:     Text.Period
   build-depends:
-                base >=4.6 && < 4.9,
+                base >=4.6 && < 5.0,
                 time >= 1.4.2,
                 old-locale >= 1.0.0.6,
                 text >= 1.2,
diff --git a/src/Text/Period.hs b/src/Text/Period.hs
--- a/src/Text/Period.hs
+++ b/src/Text/Period.hs
@@ -50,7 +50,7 @@
   | StateDay Integer Int Int
   | StateNone
 
-number :: (Read a, Integral a) => Int -> Parser a
+number :: (Read a) => Int -> Parser a
 number n = read <$> count n digit
 
 skipFieldSep :: Stream s m Char => Bool -> T.Text -> ParsecT s u m ()