diff --git a/Modules/_sre/sre.c b/Modules/_sre/sre.c
index 898ebbfe89bcd2..c0cc8268d2de50 100644
--- a/Modules/_sre/sre.c
+++ b/Modules/_sre/sre.c
@@ -1932,7 +1932,7 @@ _validate_inner(SRE_CODE *code, SRE_CODE *end, Py_ssize_t groups)
                sre_match() code is robust even if they don't, and the worst
                you can get is nonsensical match results. */
             GET_ARG;
-            if (arg > 2 * (size_t)groups + 1) {
+            if (arg >= 2 * (size_t)groups) {
                 VTRACE(("arg=%d, groups=%d\n", (int)arg, (int)groups));
                 FAIL;
             }