diff --git a/hsini.cabal b/hsini.cabal
--- a/hsini.cabal
+++ b/hsini.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name:          hsini
-version:       0.5.1.3
+version:       0.5.2
 synopsis:      ini configuration files
 description:
   Library for reading and writing configuration files in INI format (see <https://en.wikipedia.org/wiki/INI_file>).
diff --git a/src/Data/Ini/Reader/Internals.hs b/src/Data/Ini/Reader/Internals.hs
--- a/src/Data/Ini/Reader/Internals.hs
+++ b/src/Data/Ini/Reader/Internals.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE ImportQualifiedPost #-}
 
 {- |
 Module    : Data.Ini.Reader.Internals
@@ -9,11 +10,21 @@
 -}
 module Data.Ini.Reader.Internals where
 
-import Control.Monad.Except
-import Control.Monad.State
-import qualified Data.ByteString as BS
-import Text.Parsec as P
-import Text.Parsec.String
+import Control.Monad.Except (MonadError (throwError), liftM)
+import Control.Monad.State (evalState, get, put)
+import Data.ByteString qualified as BS
+import Text.Parsec as P (
+    anyChar,
+    char,
+    choice,
+    many,
+    many1,
+    manyTill,
+    newline,
+    noneOf,
+    oneOf,
+ )
+import Text.Parsec.String (Parser)
 
 import Data.Ini
 import Data.Ini.Types
@@ -45,10 +56,10 @@
 
         -- merge together OptionL and subsequent OptionContL items
         mergeOptions [] = return []
-        mergeOptions (s@(SectionL _) : ifs) = (s :) `liftM` mergeOptions ifs
-        mergeOptions (CommentL : ifs) = (CommentL :) `liftM` mergeOptions ifs
-        mergeOptions (OptionL on ov : OptionContL ov2 : ifs) = mergeOptions $ (OptionL on (ov ++ ov2)) : ifs
-        mergeOptions (o@(OptionL on ov) : ifs) = (o :) `liftM` mergeOptions ifs
+        mergeOptions (s@(SectionL _) : ifs) = (s :) `fmap` mergeOptions ifs
+        mergeOptions (CommentL : ifs) = (CommentL :) `fmap` mergeOptions ifs
+        mergeOptions (OptionL on ov : OptionContL ov2 : ifs) = mergeOptions $ OptionL on (ov ++ ov2) : ifs
+        mergeOptions (o@(OptionL on ov) : ifs) = (o :) `fmap` mergeOptions ifs
         mergeOptions _ = throwError $ IniSyntaxError "Syntax error in INI file."
 
         -- build the configuration from a [IniFile]
@@ -59,7 +70,7 @@
             let na = setOption sn on ov a
             buildit na is
      in
-        mergeOptions fIfs >>= (\is -> return . fst $ runState (buildit emptyConfig is) "default")
+        mergeOptions fIfs >>= \is -> return $ evalState (buildit emptyConfig is) "default"
 
 -- | Consumer of whitespace \"@ \t@\".
 eatWhiteSpace :: Parser String
@@ -91,9 +102,10 @@
 optLineParser :: Parser IniFile
 optLineParser =
     let
-        validOptNameChrs = ['a' .. 'z'] ++ ['A' .. 'Z'] ++ ['0' .. '9'] ++ "_-/@"
+        validOptNameChrs = ['a' .. 'z'] ++ ['A' .. 'Z'] ++ ['0' .. '9'] ++ "_-/@ "
      in
         do
+            eatWhiteSpace
             on <- many1 $ oneOf validOptNameChrs
             eatWhiteSpace
             char '='
diff --git a/tst/ReaderI.hs b/tst/ReaderI.hs
--- a/tst/ReaderI.hs
+++ b/tst/ReaderI.hs
@@ -124,6 +124,13 @@
      in
         expected @=? actual
 
+case_optLineParserAllowedChars6 =
+    let
+        expected = Right $ OptionL "foo bar" "baz"
+        actual = p2E optLineParser "optLine" "foo bar=baz\n"
+     in
+        expected @=? actual
+
 case_optLineParserDisallowedChars1 =
     let
         expected = Left "bad"
@@ -134,7 +141,7 @@
 case_optLineParserDropSpace =
     let
         expected = Right $ OptionL "foo" "bar"
-        actual = p2E optLineParser "optLine" "foo\t \t=\t \t bar\n"
+        actual = p2E optLineParser "optLine" " \tfoo\t \t=\t \t bar\n"
      in
         expected @=? actual