diff --git a/py/objstr.c b/py/objstr.c
index aba03491db..aa35d84a8e 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -1523,7 +1523,7 @@ STATIC mp_obj_t str_modulo_format(mp_obj_t pattern, size_t n_args, const mp_obj_
                     size_t slen;
                     const char *s = mp_obj_str_get_data(arg, &slen);
                     if (slen != 1) {
-                        mp_raise_TypeError("%%c needs int or char");
+                        mp_raise_TypeError("%c needs int or char");
                     }
                     mp_print_strn(&print, s, 1, flags, ' ', width);
                 } else if (arg_looks_integer(arg)) {