diff --git a/Lib/optparse.py b/Lib/optparse.py
index 8ab329104a5..87d77374232 100644
--- a/Lib/optparse.py
+++ b/Lib/optparse.py
@@ -1008,7 +1008,7 @@ class OptionContainer:
         """add_option(Option)
            add_option(opt_str, ..., kwarg=val, ...)
         """
-        if type(args[0]) is types.StringType:
+        if type(args[0]) in types.StringTypes:
             option = self.option_class(*args, **kwargs)
         elif len(args) == 1 and not kwargs:
             option = args[0]
diff --git a/Misc/NEWS b/Misc/NEWS
index 5419617b0f0..c6e79622887 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -16,6 +16,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #9161: Fix regression in optparse's acceptance of unicode
+  strings in add_option calls.
+
 - Issue #9130: Fix validation of relative imports in parser module.
 
 - Issue #9128: Fix validation of class decorators in parser module.