diff --git a/src/hal/hal.cpp b/src/hal/hal.cpp
index 2a20e100..be5d5e56 100644
--- a/src/hal/hal.cpp
+++ b/src/hal/hal.cpp
@@ -192,11 +192,16 @@ static void hal_spi_init () {
 }
 
 #if (defined(CFG_sx1261_radio) || defined(CFG_sx1262_radio))
-bit_t is_busy() {
+bit_t hal_radio_spi_is_busy() {
     // SX126x uses BUSY pin
     return digitalRead(pHalConfig->queryBusyPin()) ? true : false;
 }
-#endif
+#else
+// supply a definition just in case, because the declaration is not conditional
+bit_t hal_radio_spi_is_busy() {
+    return false;
+}
+#endif // (defined(CFG_sx1261_radio) || defined(CFG_sx1262_radio))
 
 static void hal_spi_trx(u1_t cmd, u1_t* buf, size_t len, bit_t is_read) {
     uint32_t spi_freq;
@@ -211,7 +216,7 @@ static void hal_spi_trx(u1_t cmd, u1_t* buf, size_t len, bit_t is_read) {
 
     // SX126x modems use BUSY pin. Only interact with SPI when BUSY goes LOW 
 #if (defined(CFG_sx1261_radio) || defined(CFG_sx1262_radio))
-    while (is_busy());
+    while (hal_radio_spi_is_busy());
 #endif
 
     SPI.transfer(cmd);
@@ -248,7 +253,7 @@ void hal_spi_read_sx126x(u1_t cmd, u1_t* addr, size_t addr_len, u1_t* buf, size_
     SPI.beginTransaction(settings);
     digitalWrite(nss, 0);
 
-    while (is_busy());
+    while (hal_radio_spi_is_busy());
 
     SPI.transfer(cmd);
 
diff --git a/src/lmic/hal.h b/src/lmic/hal.h
index 6195e2b0..fd92a840 100644
--- a/src/lmic/hal.h
+++ b/src/lmic/hal.h
@@ -191,7 +191,7 @@ uint8_t hal_getTxPowerPolicy(
 
 void hal_pollPendingIRQs_helper();
 void hal_processPendingIRQs(void);
-bit_t is_busy();
+bit_t hal_radio_spi_is_busy();
 
 /// \brief check for any pending interrupts: stub if interrupts are enabled.
 static inline void hal_pollPendingIRQs(void)
diff --git a/src/lmic/radio_sx126x.c b/src/lmic/radio_sx126x.c
index 1b28cf2b..ec571fd9 100644
--- a/src/lmic/radio_sx126x.c
+++ b/src/lmic/radio_sx126x.c
@@ -766,7 +766,7 @@ void radio_config(void) {
     // Perform necessary operations from STDBY_RC mode 
     if ((getStatus() | SX126x_GETSTATUS_CHIPMODE_MASK) != SX126x_CHIPMODE_STDBY_RC) {
         // Assume we've woken from sleep
-        while (is_busy());
+        while (hal_radio_spi_is_busy());
         setStandby(STDBY_RC);
     }
 
@@ -1145,7 +1145,7 @@ int radio_init(void) {
     hal_waitUntil(os_getTime()+ms2osticks(1)); // wait >100us
     hal_pin_rst(2); // configure RST pin floating!
     hal_waitUntil(os_getTime()+ms2osticks(5)); // wait 5ms
-    while(is_busy()); // wait for busy pin to go low
+    while(hal_radio_spi_is_busy()); // wait for busy pin to go low
 
     // Check default LoRa sync word to verify the reset was successful
     u1_t syncWordMSB = readRegister(LoRaSyncWordMSB);