diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 28292393d1..aad37d9509 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -11329,23 +11329,30 @@ do_pg_stop_backup(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
  * system out of backup mode, thus making it a lot more safe to call from
  * an error handler.
  *
+ * The caller can pass 'arg' as 'true' or 'false' to control whether a warning
+ * is emitted.
+ *
  * NB: This is only for aborting a non-exclusive backup that doesn't write
  * backup_label. A backup started with pg_start_backup() needs to be finished
  * with pg_stop_backup().
+ *
+ * NB: This gets used as a before_shmem_exit handler, hence the odd-looking
+ * signature.
  */
 void
-do_pg_abort_backup(void)
+do_pg_abort_backup(int code, Datum arg)
 {
+	bool	emit_warning = DatumGetBool(arg);
+
 	/*
 	 * Quick exit if session is not keeping around a non-exclusive backup
 	 * already started.
 	 */
-	if (sessionBackupState == SESSION_BACKUP_NONE)
+	if (sessionBackupState != SESSION_BACKUP_NON_EXCLUSIVE)
 		return;
 
 	WALInsertLockAcquireExclusive();
 	Assert(XLogCtl->Insert.nonExclusiveBackups > 0);
-	Assert(sessionBackupState == SESSION_BACKUP_NON_EXCLUSIVE);
 	XLogCtl->Insert.nonExclusiveBackups--;
 
 	if (XLogCtl->Insert.exclusiveBackupState == EXCLUSIVE_BACKUP_NONE &&
@@ -11354,6 +11361,25 @@ do_pg_abort_backup(void)
 		XLogCtl->Insert.forcePageWrites = false;
 	}
 	WALInsertLockRelease();
+
+	if (emit_warning)
+		ereport(WARNING,
+				(errmsg("aborting backup due to backend exiting before pg_stop_back up was called")));
+}
+
+/*
+ * Register a handler that will warn about unterminated backups at end of
+ * session, unless this has already been done.
+ */
+void
+register_persistent_abort_backup_handler(void)
+{
+	static bool already_done = false;
+
+	if (already_done)
+		return;
+	before_shmem_exit(do_pg_abort_backup, DatumGetBool(true));
+	already_done = true;
 }
 
 /*
diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index 9731742978..cc5e97c38b 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -42,18 +42,6 @@
 static StringInfo label_file;
 static StringInfo tblspc_map_file;
 
-/*
- * Called when the backend exits with a running non-exclusive base backup,
- * to clean up state.
- */
-static void
-nonexclusive_base_backup_cleanup(int code, Datum arg)
-{
-	do_pg_abort_backup();
-	ereport(WARNING,
-			(errmsg("aborting backup due to backend exiting before pg_stop_backup was called")));
-}
-
 /*
  * pg_start_backup: set up for taking an on-line backup dump
  *
@@ -101,10 +89,10 @@ pg_start_backup(PG_FUNCTION_ARGS)
 		tblspc_map_file = makeStringInfo();
 		MemoryContextSwitchTo(oldcontext);
 
+		register_persistent_abort_backup_handler();
+
 		startpoint = do_pg_start_backup(backupidstr, fast, NULL, label_file,
 										NULL, tblspc_map_file, false, true);
-
-		before_shmem_exit(nonexclusive_base_backup_cleanup, (Datum) 0);
 	}
 
 	PG_RETURN_LSN(startpoint);
@@ -246,7 +234,6 @@ pg_stop_backup_v2(PG_FUNCTION_ARGS)
 		 * and tablespace map so they can be written to disk by the caller.
 		 */
 		stoppoint = do_pg_stop_backup(label_file->data, waitforarchive, NULL);
-		cancel_before_shmem_exit(nonexclusive_base_backup_cleanup, (Datum) 0);
 
 		values[1] = CStringGetTextDatum(label_file->data);
 		values[2] = CStringGetTextDatum(tblspc_map_file->data);
diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c
index 2eba0dc21a..3e53b3df6f 100644
--- a/src/backend/replication/basebackup.c
+++ b/src/backend/replication/basebackup.c
@@ -66,7 +66,6 @@ static int64 _tarWriteDir(const char *pathbuf, int basepathlen, struct stat *sta
 			 bool sizeonly);
 static void send_int8_string(StringInfoData *buf, int64 intval);
 static void SendBackupHeader(List *tablespaces);
-static void base_backup_cleanup(int code, Datum arg);
 static void perform_base_backup(basebackup_options *opt);
 static void parse_basebackup_options(List *options, basebackup_options *opt);
 static void SendXlogRecPtrResult(XLogRecPtr ptr, TimeLineID tli);
@@ -231,17 +230,6 @@ static const struct exclude_list_item noChecksumFiles[] = {
 	{NULL, false}
 };
 
-
-/*
- * Called when ERROR or FATAL happens in perform_base_backup() after
- * we have started the backup - make sure we end it!
- */
-static void
-base_backup_cleanup(int code, Datum arg)
-{
-	do_pg_abort_backup();
-}
-
 /*
  * Actually do a base backup for the specified tablespaces.
  *
@@ -280,7 +268,7 @@ perform_base_backup(basebackup_options *opt)
 	 * do_pg_stop_backup() should be inside the error cleanup block!
 	 */
 
-	PG_ENSURE_ERROR_CLEANUP(base_backup_cleanup, (Datum) 0);
+	PG_ENSURE_ERROR_CLEANUP(do_pg_abort_backup, BoolGetDatum(false));
 	{
 		ListCell   *lc;
 		tablespaceinfo *ti;
@@ -389,7 +377,7 @@ perform_base_backup(basebackup_options *opt)
 
 		endptr = do_pg_stop_backup(labelfile->data, !opt->nowait, &endtli);
 	}
-	PG_END_ENSURE_ERROR_CLEANUP(base_backup_cleanup, (Datum) 0);
+	PG_END_ENSURE_ERROR_CLEANUP(do_pg_abort_backup, BoolGetDatum(false));
 
 
 	if (opt->includewal)
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 1d9c87cb82..e422a9dc8b 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -326,7 +326,8 @@ extern XLogRecPtr do_pg_start_backup(const char *backupidstr, bool fast,
 				   bool needtblspcmapfile);
 extern XLogRecPtr do_pg_stop_backup(char *labelfile, bool waitforarchive,
 				  TimeLineID *stoptli_p);
-extern void do_pg_abort_backup(void);
+extern void do_pg_abort_backup(int code, Datum arg);
+extern void register_persistent_abort_backup_handler(void);
 extern SessionBackupState get_backup_status(void);
 
 /* File path names (all relative to $PGDATA) */