diff --git a/src/UI/Butcher/Monadic/Flag.hs b/src/UI/Butcher/Monadic/Flag.hs
index 6a58a31..d622aaa 100644
--- a/src/UI/Butcher/Monadic/Flag.hs
+++ b/src/UI/Butcher/Monadic/Flag.hs
@@ -222,7 +222,7 @@ addFlagStringParam shorts longs name flag = addCmdPartInpA desc parseF (\_ -> pu
         [drop (length s + 1) str | (s ++ " ") `isPrefixOf` str]
       of
         Nothing -> _flag_default flag <&> \x -> (x, InputString str)
-        Just rest1 -> let (x, rest2) = break (not . Char.isSpace) rest1
+        Just rest1 -> let (x, rest2) = break Char.isSpace $ dropWhile Char.isSpace rest1
                       in Just (x, InputString rest2)
     parseF (InputArgs (s1:s2:sr)) | any (==s1) allStrs = Just (s2, InputArgs sr)
     parseF inp@(InputArgs _) = _flag_default flag <&> \x -> (x, inp)
@@ -274,7 +274,7 @@ addFlagStringParamsAll shorts longs name flag act = addCmdPartManyInpA desc pars
       $ \s -> [ (x, InputString rest2)
               | (s ++ " ") `isPrefixOf` str
               , let rest1 = drop (length s + 1) str
-              , let (x, rest2) = break (not . Char.isSpace) rest1
+              , let (x, rest2) = break Char.isSpace $ dropWhile Char.isSpace rest1
               ]
     parseF (InputArgs (s1:s2:sr))
       = flip firstJust allStrs
diff --git a/src/UI/Butcher/Monadic/Param.hs b/src/UI/Butcher/Monadic/Param.hs
index 101127b..4262736 100644
--- a/src/UI/Butcher/Monadic/Param.hs
+++ b/src/UI/Butcher/Monadic/Param.hs
@@ -105,7 +105,7 @@ addStringParam name par = addCmdPartInp desc parseF
          $ PartVariable name
     parseF :: Input -> Maybe (String, Input)
     parseF (InputString str)
-      = case break (not . Char.isSpace) str of
+      = case break Char.isSpace $ dropWhile Char.isSpace str of
           ("", rest) -> _param_default par <&> \x -> (x, InputString rest)
           (x, rest) -> Just (x, InputString rest)
     parseF (InputArgs args) = case args of
@@ -125,7 +125,7 @@ addStringParamOpt name par = addCmdPartInp desc parseF
          $ PartVariable name
     parseF :: Input -> Maybe (Maybe String, Input)
     parseF (InputString str)
-      = case break (not . Char.isSpace) str of
+      = case break Char.isSpace $ dropWhile Char.isSpace str of
           ("", rest) -> Just (Nothing, InputString rest)
           (x, rest) -> Just (Just x, InputString rest)
     parseF (InputArgs args) = case args of