diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml
index 4c5ed1e6d6..3fec491bbe 100644
--- a/doc/src/sgml/protocol.sgml
+++ b/doc/src/sgml/protocol.sgml
@@ -2552,6 +2552,14 @@ The commands accepted in walsender mode are:
          with <filename>pgsql_tmp</filename>.
         </para>
        </listitem>
+       <listitem>
+        <para>
+         Unlogged relations, except for the init fork which is required to
+         recreate the (empty) unlogged relation on recovery.  Unlogged tables
+         created during a backup may be copied, but will be excluded from the
+         next backup.
+        </para>
+       </listitem>
        <listitem>
         <para>
          <filename>pg_wal</filename>, including subdirectories. If the backup is run
diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c
index dd7ad64862..1a5c91de17 100644
--- a/src/backend/replication/basebackup.c
+++ b/src/backend/replication/basebackup.c
@@ -26,6 +26,7 @@
 #include "nodes/pg_list.h"
 #include "pgtar.h"
 #include "pgstat.h"
+#include "port.h"
 #include "postmaster/syslogger.h"
 #include "replication/basebackup.h"
 #include "replication/walsender.h"
@@ -33,6 +34,7 @@
 #include "storage/dsm_impl.h"
 #include "storage/fd.h"
 #include "storage/ipc.h"
+#include "storage/reinit.h"
 #include "utils/builtins.h"
 #include "utils/elog.h"
 #include "utils/ps_status.h"
@@ -959,6 +961,36 @@ sendDir(const char *path, int basepathlen, bool sizeonly, List *tablespaces,
 	char		pathbuf[MAXPGPATH * 2];
 	struct stat statbuf;
 	int64		size = 0;
+	HTAB 		*unloggedHash = NULL;	/* Unlogged tables in this path. */
+	const char 	*unloggedDelim;			/* Split this path from parent path. */
+
+	/*
+	 * Find any unlogged relations in this path and store them in a hash. All
+	 * unlogged relation forks except init will be excluded from the backup.
+	 *
+	 * Start by finding the location of the delimiter between the parent
+	 * path and the current path.
+	 */
+	unloggedDelim = last_dir_separator(path);
+
+	/* Does this path look like a database path (i.e. all digits)? */
+	if (unloggedDelim != NULL &&
+		strspn(unloggedDelim + 1, "0123456789") == strlen(unloggedDelim + 1))
+	{
+		/* Part of path that contains the parent directory. */
+		int parentPathLen = unloggedDelim - path;
+
+		/*
+		 * Build the unlogged relation hash if the parent path is either
+		 * $PGDATA/base or a tablespace version path.
+		 */
+		if (strncmp(path, "./base", parentPathLen) == 0 ||
+			(parentPathLen >= (sizeof(TABLESPACE_VERSION_DIRECTORY) - 1) &&
+			 strncmp(unloggedDelim - (sizeof(TABLESPACE_VERSION_DIRECTORY) - 1),
+					 TABLESPACE_VERSION_DIRECTORY,
+					 sizeof(TABLESPACE_VERSION_DIRECTORY) - 1) == 0))
+			unloggedHash = ResetUnloggedRelationsHash(path);
+	}
 
 	dir = AllocateDir(path);
 	while ((de = ReadDir(dir, path)) != NULL)
@@ -1008,6 +1040,15 @@ sendDir(const char *path, int basepathlen, bool sizeonly, List *tablespaces,
 		if (excludeFound)
 			continue;
 
+		/* Exclude all forks for unlogged tables except the init fork. */
+		if (unloggedHash && ResetUnloggedRelationsMatch(
+				unloggedHash, de->d_name) == unloggedOther)
+		{
+			elog(DEBUG2, "unlogged relation file \"%s\" excluded from backup",
+				 de->d_name);
+			continue;
+		}
+
 		snprintf(pathbuf, sizeof(pathbuf), "%s/%s", path, de->d_name);
 
 		/* Skip pg_control here to back up it last */
@@ -1177,6 +1218,11 @@ sendDir(const char *path, int basepathlen, bool sizeonly, List *tablespaces,
 					(errmsg("skipping special file \"%s\"", pathbuf)));
 	}
 	FreeDir(dir);
+
+	/* Free the hash containing unlogged tables, if it was created */
+	if (unloggedHash != NULL)
+		hash_destroy(unloggedHash);
+
 	return size;
 }
 
diff --git a/src/bin/pg_basebackup/t/010_pg_basebackup.pl b/src/bin/pg_basebackup/t/010_pg_basebackup.pl
index cdf4f5be37..455c7fca0d 100644
--- a/src/bin/pg_basebackup/t/010_pg_basebackup.pl
+++ b/src/bin/pg_basebackup/t/010_pg_basebackup.pl
@@ -4,7 +4,7 @@ use Cwd;
 use Config;
 use PostgresNode;
 use TestLib;
-use Test::More tests => 79;
+use Test::More tests => 87;
 
 program_help_ok('pg_basebackup');
 program_version_ok('pg_basebackup');
@@ -66,6 +66,16 @@ foreach my $filename (
 # positive.
 $node->safe_psql('postgres', 'SELECT 1;');
 
+# Create an unlogged table to test that forks other than init are not copied.
+$node->safe_psql('postgres', 'CREATE UNLOGGED TABLE base_unlogged (id int)');
+
+my $baseUnloggedPath = $node->safe_psql('postgres',
+	q{select pg_relation_filepath('base_unlogged')});
+
+# Make sure main and init forks exist
+ok(-f "$pgdata/${baseUnloggedPath}_init", 'unlogged init fork in base');
+ok(-f "$pgdata/$baseUnloggedPath", 'unlogged main fork in base');
+
 $node->command_ok([ 'pg_basebackup', '-D', "$tempdir/backup", '-X', 'none' ],
 	'pg_basebackup runs');
 ok(-f "$tempdir/backup/PG_VERSION", 'backup was created');
@@ -96,6 +106,12 @@ foreach my $filename (
 	ok(!-f "$tempdir/backup/$filename", "$filename not copied");
 }
 
+# Unlogged relation forks other than init should not be copied
+ok(-f "$tempdir/backup/${baseUnloggedPath}_init",
+	'unlogged init fork in backup');
+ok(!-f "$tempdir/backup/$baseUnloggedPath",
+	'unlogged main fork not in backup');
+
 # Make sure existing backup_label was ignored.
 isnt(slurp_file("$tempdir/backup/backup_label"),
 	'DONOTCOPY', 'existing backup_label not copied');
@@ -147,7 +163,7 @@ unlink "$pgdata/$superlongname";
 # skip on Windows.
 SKIP:
 {
-	skip "symlinks not supported on Windows", 11 if ($windows_os);
+	skip "symlinks not supported on Windows", 15 if ($windows_os);
 
 	# Move pg_replslot out of $pgdata and create a symlink to it.
 	$node->stop;
@@ -177,6 +193,19 @@ SKIP:
 	my @tblspc_tars = glob "$tempdir/tarbackup2/[0-9]*.tar";
 	is(scalar(@tblspc_tars), 1, 'one tablespace tar was created');
 
+	# Create an unlogged table to test that forks other than init are not copied.
+	$node->safe_psql('postgres',
+		'CREATE UNLOGGED TABLE tblspc1_unlogged (id int) TABLESPACE tblspc1;');
+
+	my $tblspc1UnloggedPath = $node->safe_psql(
+		'postgres', q{select pg_relation_filepath('tblspc1_unlogged')});
+
+	# Make sure main and init forks exist
+	ok(-f "$pgdata/${tblspc1UnloggedPath}_init",
+		'unlogged init fork in tablespace');
+	ok(-f "$pgdata/$tblspc1UnloggedPath",
+		'unlogged main fork in tablespace');
+
 	$node->command_fails(
 		[ 'pg_basebackup', '-D', "$tempdir/backup1", '-Fp' ],
 		'plain format with tablespaces fails without tablespace mapping');
@@ -195,11 +224,20 @@ SKIP:
 		"tablespace symlink was updated");
 	closedir $dh;
 
+	# Unlogged relation forks other than init should not be copied
+	my ($tblspc1UnloggedBackupPath) = $tblspc1UnloggedPath =~ /[^\/]*\/[^\/]*\/[^\/]*$/g;
+
+	ok(-f "$tempdir/tbackup/tblspc1/${tblspc1UnloggedBackupPath}_init",
+		'unlogged init fork in tablespace backup');
+	ok(!-f "$tempdir/tbackup/tblspc1/$tblspc1UnloggedBackupPath",
+		'unlogged main fork not in tablespace backup');
+
 	ok( -d "$tempdir/backup1/pg_replslot",
 		'pg_replslot symlink copied as directory');
 
 	mkdir "$tempdir/tbl=spc2";
 	$node->safe_psql('postgres', "DROP TABLE test1;");
+	$node->safe_psql('postgres', "DROP TABLE tblspc1_unlogged;");
 	$node->safe_psql('postgres', "DROP TABLESPACE tblspc1;");
 	$node->safe_psql('postgres',
 		"CREATE TABLESPACE tblspc2 LOCATION '$shorter_tempdir/tbl=spc2';");