-#define ao_sdcard_get_slow() ao_spi_get(AO_SDCARD_SPI_BUS, AO_SPI_SPEED_250kHz)
-#define ao_sdcard_get() ao_spi_get(AO_SDCARD_SPI_BUS, AO_SPI_SPEED_FAST)
-#define ao_sdcard_put() ao_spi_put(AO_SDCARD_SPI_BUS)
+#if HAS_RADIO
+extern uint8_t ao_radio_mutex;
+#define get_radio() ao_mutex_get(&ao_radio_mutex)
+#define put_radio() ao_mutex_put(&ao_radio_mutex)
+#else
+#define get_radio()
+#define put_radio()
+#endif
+
+#define ao_sdcard_get_slow() do { get_radio(); ao_spi_get(AO_SDCARD_SPI_BUS, AO_SPI_SPEED_250kHz); } while (0)
+#define ao_sdcard_get() do { get_radio(); ao_spi_get(AO_SDCARD_SPI_BUS, AO_SPI_SPEED_FAST); } while (0)
+#define ao_sdcard_put() do { ao_spi_put(AO_SDCARD_SPI_BUS); put_radio(); } while (0)