diff --git a/Lib/ConfigParser.py b/Lib/ConfigParser.py
index 9d55ca76283..14412a38bae 100644
--- a/Lib/ConfigParser.py
+++ b/Lib/ConfigParser.py
@@ -391,7 +391,7 @@ def remove_section(self, section):
         r'\]'                                 # ]
         )
     OPTCRE = re.compile(
-        r'(?P<option>[-\w_.*,(){}]+)'         # a lot of stuff found by IvL
+        r'(?P<option>[]\-[\w_.*,(){}]+)'      # a lot of stuff found by IvL
         r'[ \t]*(?P<vi>[:=])[ \t]*'           # any number of space/tab,
                                               # followed by separator
                                               # (either : or =), followed