diff --git a/Lib/shlex.py b/Lib/shlex.py
index e87266f..daaf4e2 100644
--- a/Lib/shlex.py
+++ b/Lib/shlex.py
@@ -59,11 +59,7 @@ class shlex:
         if punctuation_chars:
             # _pushback_chars is a push back queue used by lookahead logic
             self._pushback_chars = deque()
-            # these chars added because allowed in file names, args, wildcards
-            self.wordchars += '~-./*?='
-            #remove any punctuation chars from wordchars
-            t = self.wordchars.maketrans(dict.fromkeys(punctuation_chars))
-            self.wordchars = self.wordchars.translate(t)
+            self.whitespace_split = True
 
     def push_token(self, tok):
         "Push a token onto the stack popped by the get_token method"
@@ -246,7 +242,7 @@ class shlex:
                         self.state = ' '
                         break
                 elif (nextchar in self.wordchars or nextchar in self.quotes
-                      or self.whitespace_split):
+                      or (self.whitespace_split and nextchar not in self.punctuation_chars)):
                     self.token += nextchar
                 else:
                     if self.punctuation_chars:
diff --git a/Lib/test/test_shlex.py b/Lib/test/test_shlex.py
index 3936c97..fb2b6df 100644
--- a/Lib/test/test_shlex.py
+++ b/Lib/test/test_shlex.py
@@ -229,8 +229,8 @@ class ShlexTest(unittest.TestCase):
 
     def testSyntaxSplitCustom(self):
         """Test handling of syntax splitting with custom chars"""
-        ref = ['~/a', '&', '&', 'b-c', '--color=auto', '||', 'd', '*.py?']
-        ss = "~/a && b-c --color=auto || d *.py?"
+        ref = ['~/a&&b-c', '--color=auto', '||', 'd', '*.py?']
+        ss = "~/a&&b-c --color=auto||d *.py?"
         s = shlex.shlex(ss, punctuation_chars="|")
         result = list(s)
         self.assertEqual(ref, result, "While splitting '%s'" % ss)
@@ -255,20 +255,14 @@ class ShlexTest(unittest.TestCase):
                 observed.append((t, tt))
             self.assertEqual(observed, expected)
 
-    def testPunctuationInWordChars(self):
-        """Test that any punctuation chars are removed from wordchars"""
-        s = shlex.shlex('a_b__c', punctuation_chars='_')
-        self.assertNotIn('_', s.wordchars)
-        self.assertEqual(list(s), ['a', '_', 'b', '__', 'c'])
-
     def testPunctuationWithWhitespaceSplit(self):
         """Test that with whitespace_split, behaviour is as expected"""
         s = shlex.shlex('a  && b  ||  c', punctuation_chars='&')
+        s.whitespace_split = False
         # whitespace_split is False, so splitting will be based on
         # punctuation_chars
         self.assertEqual(list(s), ['a', '&&', 'b', '|', '|', 'c'])
         s = shlex.shlex('a  && b  ||  c', punctuation_chars='&')
-        s.whitespace_split = True
         # whitespace_split is True, so splitting will be based on
         # white space
         self.assertEqual(list(s), ['a', '&&', 'b', '||', 'c'])