diff --git a/samples/net/cellular_modem/boards/nrf9160dk_nrf52840.conf b/samples/net/cellular_modem/boards/nrf9160dk_nrf52840.conf
index 161f2d7176b..ae48071eeb5 100644
--- a/samples/net/cellular_modem/boards/nrf9160dk_nrf52840.conf
+++ b/samples/net/cellular_modem/boards/nrf9160dk_nrf52840.conf
@@ -1,4 +1,6 @@
 CONFIG_UART_ASYNC_API=y
+CONFIG_UART_1_ASYNC=y
+CONFIG_UART_1_INTERRUPT_DRIVEN=n
 # Enable HW RX byte counting. This especially matters at higher baud rates.
 CONFIG_UART_1_NRF_HW_ASYNC=y
 CONFIG_UART_1_NRF_HW_ASYNC_TIMER=1
diff --git a/samples/net/cellular_modem/boards/nrf9160dk_nrf9160_ns.conf b/samples/net/cellular_modem/boards/nrf9160dk_nrf9160_ns.conf
index b0866d8c86c..045f9eb4338 100644
--- a/samples/net/cellular_modem/boards/nrf9160dk_nrf9160_ns.conf
+++ b/samples/net/cellular_modem/boards/nrf9160dk_nrf9160_ns.conf
@@ -1,4 +1,6 @@
 CONFIG_UART_ASYNC_API=y
+CONFIG_UART_1_ASYNC=y
+CONFIG_UART_1_INTERRUPT_DRIVEN=n
 # Enable HW RX byte counting. This especially matters at higher baud rates.
 CONFIG_UART_1_NRF_HW_ASYNC=y
 CONFIG_UART_1_NRF_HW_ASYNC_TIMER=1