diff --git a/src/backend/statistics/attribute_stats.c b/src/backend/statistics/attribute_stats.c
index 50f89ff0ac3..56293d94104 100644
--- a/src/backend/statistics/attribute_stats.c
+++ b/src/backend/statistics/attribute_stats.c
@@ -243,8 +243,8 @@ attribute_statistics_update(FunctionCallInfo fcinfo)
 	inherited = PG_GETARG_BOOL(INHERITED_ARG);
 
 	/*
-	 * Check argument sanity. If some arguments are unusable, emit a WARNING
-	 * and set the corresponding argument to NULL in fcinfo.
+	 * Check argument sanity.  If some arguments are unusable, emit a WARNING
+	 * and skip the corresponding statistics kind, reporting back a failure.
 	 */
 
 	if (!stats_check_arg_array(fcinfo, attarginfo, MOST_COMMON_FREQS_ARG))