diff --git a/Lib/traceback.py b/Lib/traceback.py
index 457d925..4e008bc 100644
--- a/Lib/traceback.py
+++ b/Lib/traceback.py
@@ -525,7 +525,8 @@ def __init__(self, exc_type, exc_value, exc_traceback, *, limit=None,
         if exc_type and issubclass(exc_type, SyntaxError):
             # Handle SyntaxError's specially
             self.filename = exc_value.filename
-            self.lineno = str(exc_value.lineno)
+            lno = exc_value.lineno
+            self.lineno = str(lno) if lno is not None else None
             self.text = exc_value.text
             self.offset = exc_value.offset
             self.msg = exc_value.msg
@@ -584,9 +585,12 @@ def format_exception_only(self):
     def _format_syntax_error(self, stype):
         """Format SyntaxError exceptions (internal helper)."""
         # Show exactly where the problem was found.
-        filename = self.filename or "<string>"
-        lineno = str(self.lineno) or '?'
-        yield '  File "{}", line {}\n'.format(filename, lineno)
+        filename_suffix = ''
+        if self.lineno is not None:
+            yield '  File "{}", line {}\n'.format(
+                self.filename or "<string>", self.lineno)
+        elif self.filename is not None:
+            filename_suffix = ' ({})'.format(self.filename)
 
         text = self.text
         if text is not None:
@@ -604,7 +608,7 @@ def _format_syntax_error(self, stype):
                 caretspace = ((c if c.isspace() else ' ') for c in ltext[:caret])
                 yield '    {}^\n'.format(''.join(caretspace))
         msg = self.msg or "<no detail available>"
-        yield "{}: {}\n".format(stype, msg)
+        yield "{}: {}{}\n".format(stype, msg, filename_suffix)
 
     def format(self, *, chain=True):
         """Format the exception.