diff --git a/lib/postgrex/extensions/int8.ex b/lib/postgrex/extensions/int8.ex
index 04a554b4..89e5128a 100644
--- a/lib/postgrex/extensions/int8.ex
+++ b/lib/postgrex/extensions/int8.ex
@@ -1,7 +1,7 @@
 defmodule Postgrex.Extensions.Int8 do
   @moduledoc false
   import Postgrex.BinaryUtils, warn: false
-  use Postgrex.BinaryExtension, send: "int8send"
+  use Postgrex.BinaryExtension, send: "int8send", send: "pg_lsn_send"
 
   @int8_range -9_223_372_036_854_775_808..9_223_372_036_854_775_807
 
diff --git a/test/query_test.exs b/test/query_test.exs
index eb811db5..1eb4b2c0 100644
--- a/test/query_test.exs
+++ b/test/query_test.exs
@@ -58,6 +58,12 @@ defmodule QueryTest do
     assert [[Decimal.new("NaN")]] == query("SELECT 'NaN'::numeric", [])
   end
 
+  @tag min_pg_version: "10.0"
+  test "decode lsn", context do
+    assert [[int, text]] = query("SELECT pg_current_wal_lsn(), pg_current_wal_lsn()::text", [])
+    assert Postgrex.ReplicationConnection.decode_lsn(text) == {:ok, int}
+  end
+
   @tag min_pg_version: "14.0"
   test "decode numeric infinity", context do
     assert [[Decimal.new("Inf")]] == query("SELECT NUMERIC 'Infinity'", [])