diff --git a/firmware/common/hackrf-ui.c b/firmware/common/hackrf-ui.c
index 0b85e777..079cfd9e 100644
--- a/firmware/common/hackrf-ui.c
+++ b/firmware/common/hackrf-ui.c
@@ -59,12 +59,16 @@ static const hackrf_ui_t hackrf_ui_null = {
 	&hackrf_ui_set_antenna_bias_null,
 };
 
+const hackrf_ui_t* portapack_detect(void) __attribute__((weak));
+
 static const hackrf_ui_t* ui = NULL;
 
 const hackrf_ui_t* hackrf_ui(void) {
 	/* Detect on first use. If no UI hardware is detected, use a stub function table. */
 	if( ui == NULL ) {
-		ui = portapack_detect();
+		if( portapack_detect ) {
+			ui = portapack_detect();
+		}
 		if( ui == NULL ) {
 			ui = &hackrf_ui_null;
 		}
diff --git a/firmware/hackrf-common.cmake b/firmware/hackrf-common.cmake
index 0d577251..88b83b77 100644
--- a/firmware/hackrf-common.cmake
+++ b/firmware/hackrf-common.cmake
@@ -127,6 +127,7 @@ macro(DeclareTargets)
 		${PATH_HACKRF_FIRMWARE_COMMON}/spi_bus.c
 		${PATH_HACKRF_FIRMWARE_COMMON}/spi_ssp.c
 		${PATH_HACKRF_FIRMWARE_COMMON}/gpio_lpc.c
+		${PATH_HACKRF_FIRMWARE_COMMON}/hackrf-ui.c
 	)
 
 	if(BOARD STREQUAL "RAD1O")
@@ -140,12 +141,6 @@ macro(DeclareTargets)
 			${SRC_M4}
 			${PATH_HACKRF_FIRMWARE_COMMON}/rffc5071.c
 			${PATH_HACKRF_FIRMWARE_COMMON}/rffc5071_spi.c
-			${PATH_HACKRF_FIRMWARE_COMMON}/cpld_jtag.c
-			${PATH_HACKRF_FIRMWARE_COMMON}/xapp058/lenval.c
-			${PATH_HACKRF_FIRMWARE_COMMON}/xapp058/micro.c
-			${PATH_HACKRF_FIRMWARE_COMMON}/xapp058/ports.c
-			${PATH_HACKRF_FIRMWARE_COMMON}/hackrf-ui.c
-			${PATH_HACKRF_FIRMWARE_COMMON}/ui_portapack.c
 		)
 	endif()
 
diff --git a/firmware/hackrf_usb/CMakeLists.txt b/firmware/hackrf_usb/CMakeLists.txt
index b8fb3577..5c9e3935 100644
--- a/firmware/hackrf_usb/CMakeLists.txt
+++ b/firmware/hackrf_usb/CMakeLists.txt
@@ -46,10 +46,21 @@ set(SRC_M4
 	usb_api_sweep.c
 	"${PATH_HACKRF_FIRMWARE_COMMON}/usb_queue.c"
 	"${PATH_HACKRF_FIRMWARE_COMMON}/fault_handler.c"
+	"${PATH_HACKRF_FIRMWARE_COMMON}/cpld_jtag.c"
 	"${PATH_HACKRF_FIRMWARE_COMMON}/cpld_xc2c.c"
+	"${PATH_HACKRF_FIRMWARE_COMMON}/xapp058/lenval.c"
+	"${PATH_HACKRF_FIRMWARE_COMMON}/xapp058/micro.c"
+	"${PATH_HACKRF_FIRMWARE_COMMON}/xapp058/ports.c"
 	"${PATH_HACKRF_FIRMWARE_COMMON}/crc.c"
 	"${PATH_HACKRF_FIRMWARE_COMMON}/rom_iap.c"
 	"${PATH_HACKRF_FIRMWARE_COMMON}/operacake.c"
 )
 
+if(NOT BOARD STREQUAL "RAD1O")
+	SET(SRC_M4
+		${SRC_M4}
+		"${PATH_HACKRF_FIRMWARE_COMMON}/ui_portapack.c"
+	)
+endif()
+
 DeclareTargets()