diff --git a/asyncpg/pgproto b/asyncpg/pgproto
index a4178145..591c9061 160000
--- a/asyncpg/pgproto
+++ b/asyncpg/pgproto
@@ -1 +1 @@
-Subproject commit a4178145cd7cc3a44eee20cfc9e8b94a7fed2053
+Subproject commit 591c906121dbfc4f479ac521bf2cd90cbccea360
diff --git a/tests/test_connect.py b/tests/test_connect.py
index 7707a1c9..fd1da530 100644
--- a/tests/test_connect.py
+++ b/tests/test_connect.py
@@ -77,6 +77,15 @@ async def test_get_settings_01(self):
         self.assertEqual(
             self.con.get_settings().client_encoding,
             'UTF8')
+        await self.con.execute("set client_encoding to 'sql-ascii'")
+        self.assertEqual(self.con.get_settings().client_encoding, "SQL_ASCII")
+
+    async def test_client_encoding(self):
+        await self.con.execute("set client_encoding to 'sql-ascii'")
+        encoding = await self.con.fetchval("show client_encoding")
+        self.assertEqual(encoding, "SQL_ASCII")
+        encoding = await self.con.fetchval("select $1", encoding)
+        self.assertEqual(encoding, "SQL_ASCII")
 
     async def test_server_version_01(self):
         version = self.con.get_server_version()