bpo-2091: Fix typo in exception message (GH-12987)

diff --git a/Modules/_io/_iomodule.c b/Modules/_io/_iomodule.c
index 965c4846bdb8b46f9a3dd5da5d48eed5eceb792d..d482142d0804043324702a18eeaa3c4ecd45e882 100644 (file)
--- a/Modules/_io/_iomodule.c
+++ b/Modules/_io/_iomodule.c
@@ -324,7 +324,7 @@ _io_open_impl(PyObject *module, PyObject *file, const char *mode,
     if (universal) {
         if (creating || writing || appending || updating) {
             PyErr_SetString(PyExc_ValueError,
-                            "mode U cannot be combined with x', 'w', 'a', or '+'");
+                            "mode U cannot be combined with 'x', 'w', 'a', or '+'");
             goto error;
         }
         if (PyErr_WarnEx(PyExc_DeprecationWarning,