diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 5ae0078b86e..311cf4c0d3a 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -180,6 +180,7 @@ typedef struct autovac_table
 	int			at_vacuum_cost_limit;
 	bool		at_dobalance;
 	bool		at_wraparound;
+	bool		at_sharedrel;
 	char	   *at_relname;
 	char	   *at_nspname;
 	char	   *at_datname;
@@ -193,6 +194,7 @@ typedef struct autovac_table
  * wi_links		entry into free list or running list
  * wi_dboid		OID of the database this worker is supposed to work on
  * wi_tableoid	OID of the table currently being vacuumed, if any
+ * wi_sharedrel	flag indicating whether table is marked relisshared
  * wi_proc		pointer to PGPROC of the running worker, NULL if not started
  * wi_launchtime Time at which this worker was launched
  * wi_cost_*	Vacuum cost-based delay parameters current in this worker
@@ -210,6 +212,7 @@ typedef struct WorkerInfoData
 	PGPROC	   *wi_proc;
 	TimestampTz wi_launchtime;
 	bool		wi_dobalance;
+	bool		wi_sharedrel;
 	int			wi_cost_delay;
 	int			wi_cost_limit;
 	int			wi_cost_limit_base;
@@ -742,6 +745,7 @@ AutoVacLauncherMain(int argc, char *argv[])
 					worker = AutoVacuumShmem->av_startingWorker;
 					worker->wi_dboid = InvalidOid;
 					worker->wi_tableoid = InvalidOid;
+					worker->wi_sharedrel = false;
 					worker->wi_proc = NULL;
 					worker->wi_launchtime = 0;
 					worker->wi_links.next = (SHM_QUEUE *) AutoVacuumShmem->av_freeWorkers;
@@ -1700,6 +1704,7 @@ FreeWorkerInfo(int code, Datum arg)
 		MyWorkerInfo->wi_links.next = (SHM_QUEUE *) AutoVacuumShmem->av_freeWorkers;
 		MyWorkerInfo->wi_dboid = InvalidOid;
 		MyWorkerInfo->wi_tableoid = InvalidOid;
+		MyWorkerInfo->wi_sharedrel = false;
 		MyWorkerInfo->wi_proc = NULL;
 		MyWorkerInfo->wi_launchtime = 0;
 		MyWorkerInfo->wi_dobalance = false;
@@ -2227,8 +2232,8 @@ do_autovacuum(void)
 			if (worker == MyWorkerInfo)
 				goto next_worker;
 
-			/* ignore workers in other databases */
-			if (worker->wi_dboid != MyDatabaseId)
+			/* ignore workers in other databases (unless table is shared) */
+			if (!worker->wi_sharedrel && worker->wi_dboid != MyDatabaseId)
 				goto next_worker;
 
 			if (worker->wi_tableoid == relid)
@@ -2273,6 +2278,7 @@ do_autovacuum(void)
 		 * the lock so that other workers don't vacuum it concurrently.
 		 */
 		MyWorkerInfo->wi_tableoid = relid;
+		MyWorkerInfo->wi_sharedrel = tab->at_sharedrel;
 		LWLockRelease(AutovacuumScheduleLock);
 
 		/*
@@ -2384,6 +2390,7 @@ deleted:
 		 */
 		LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
 		MyWorkerInfo->wi_tableoid = InvalidOid;
+		MyWorkerInfo->wi_sharedrel = false;
 		LWLockRelease(AutovacuumLock);
 
 		/* restore vacuum cost GUCs for the next iteration */
@@ -2558,6 +2565,7 @@ table_recheck_autovac(Oid relid, HTAB *table_toast_map,
 
 		tab = palloc(sizeof(autovac_table));
 		tab->at_relid = relid;
+		tab->at_sharedrel = classForm->relisshared;
 		tab->at_dovacuum = dovacuum;
 		tab->at_doanalyze = doanalyze;
 		tab->at_freeze_min_age = freeze_min_age;