diff --git a/Lib/email/_header_value_parser.py b/Lib/email/_header_value_parser.py
index 9b9697f77346a60..539f41935ed49c6 100644
--- a/Lib/email/_header_value_parser.py
+++ b/Lib/email/_header_value_parser.py
@@ -141,7 +141,7 @@ def append_if_fits(self, token, stoken=None):
                 self.stickyspace = None
                 self.firstline = False
                 return True
-            if token.has_fws:
+            if token.has_leading_fws:
                 ws = token.pop_leading_fws()
                 if ws is not None:
                     self.stickyspace += str(ws)
@@ -267,7 +267,7 @@ def startswith_fws(self):
         return self[0].startswith_fws()
 
     def pop_leading_fws(self):
-        if self[0].token_type == 'fws':
+        if self[0].token_type == 'fws' or self[0].token_type == 'cfws':
             return self.pop(0)
         return self[0].pop_leading_fws()
 
@@ -283,6 +283,14 @@ def has_fws(self):
                 return True
         return False
 
+    @property
+    def has_leading_fws(self):
+        for part in self:
+            if part.has_fws:
+                return True
+            break
+        return False
+
     def has_leading_comment(self):
         return self[0].has_leading_comment()
 
@@ -1292,6 +1300,8 @@ def startswith_fws(self):
 
     has_fws = True
 
+    has_leading_fws = True
+
 
 class ValueTerminal(Terminal):
 
@@ -1304,6 +1314,8 @@ def startswith_fws(self):
 
     has_fws = False
 
+    has_leading_fws = False
+
     def as_encoded_word(self, charset):
         return _ew.encode(str(self), charset)
 
@@ -1323,6 +1335,8 @@ def __str__(self):
 
     has_fws = True
 
+    has_leading_fws = True
+
 
 # XXX these need to become classes and used as instances so
 # that a program can't change them in a parse tree and screw
diff --git a/Lib/test/test_email/test__header_value_parser.py b/Lib/test/test_email/test__header_value_parser.py
index e0ec87d2080185d..5d4a714f845531b 100644
--- a/Lib/test/test_email/test__header_value_parser.py
+++ b/Lib/test/test_email/test__header_value_parser.py
@@ -2723,5 +2723,14 @@ def test_long_filename_attachment(self):
             folded
         )
 
+    def test_long_filename_attachment_with_space(self):
+        folded = self.policy.fold('Content-Disposition', 'attachment; filename="1234 67890123456789012345678901234567890123456789012345678901234567890"')
+        self.assertEqual(
+            'Content-Disposition: attachment;\n filename="1234 67890123456789012345678901234567890123456789012345678901234567890"\n',
+            folded
+        )
+
+
+
 if __name__ == '__main__':
     unittest.main()