diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 8996d36..769fd0e 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -249,6 +249,10 @@ lazy_vacuum_rel(Relation onerel, int options, VacuumParams *params,
 	if (options & VACOPT_DISABLE_PAGE_SKIPPING)
 		aggressive = true;
 
+	/* Sanity check: an anti-wraparound vacuum must be an aggressive vacuum */
+	if (params->is_wraparound)
+		Assert(aggressive);
+
 	vacrelstats = (LVRelStats *) palloc0(sizeof(LVRelStats));
 
 	vacrelstats->old_rel_pages = onerel->rd_rel->relpages;
@@ -376,10 +380,8 @@ lazy_vacuum_rel(Relation onerel, int options, VacuumParams *params,
 			initStringInfo(&buf);
 			if (params->is_wraparound)
 			{
-				if (aggressive)
-					msgfmt = _("automatic aggressive vacuum to prevent wraparound of table \"%s.%s.%s\": index scans: %d\n");
-				else
-					msgfmt = _("automatic vacuum to prevent wraparound of table \"%s.%s.%s\": index scans: %d\n");
+				/* autovacuum cannot be anti-wraparound and not aggressive vacuum */
+				msgfmt = _("automatic aggressive vacuum to prevent wraparound of table \"%s.%s.%s\": index scans: %d\n");
 			}
 			else
 			{