diff --git a/src/backend/utils/adt/bool.c b/src/backend/utils/adt/bool.c
index 340607f936..26f9ea04b4 100644
--- a/src/backend/utils/adt/bool.c
+++ b/src/backend/utils/adt/bool.c
@@ -82,7 +82,7 @@ parse_bool_with_len(const char *value, size_t len, bool *result)
 					*result = true;
 				return true;
 			}
-			else if (pg_strncasecmp(value, "off", (len > 2 ? len : 2)) == 0)
+			else if (pg_strncasecmp(value, "off", (len > 3 ? len : 3)) == 0)
 			{
 				if (result)
 					*result = false;