diff --git a/src/mame/drivers/apple2gs.cpp b/src/mame/drivers/apple2gs.cpp
index fad0eb35530..b1c42bec41d 100644
--- a/src/mame/drivers/apple2gs.cpp
+++ b/src/mame/drivers/apple2gs.cpp
@@ -4925,6 +4925,7 @@ void apple2gs_state::apple2gs(machine_config &config)
 
 	/* serial */
 	SCC85C30(config, m_scc, A2GS_14M/2);
+	m_scc->configure_channels(3'686'400, 3'686'400, 3'686'400, 3'686'400);
 	m_scc->out_int_callback().set(FUNC(apple2gs_state::scc_irq_w));
 	m_scc->out_txda_callback().set("printer", FUNC(rs232_port_device::write_txd));
 	m_scc->out_txdb_callback().set("modem", FUNC(rs232_port_device::write_txd));