diff --git a/libraries/AP_HAL_ChibiOS/RCInput.cpp b/libraries/AP_HAL_ChibiOS/RCInput.cpp
index e36f70cb24..72c5c426d9 100644
--- a/libraries/AP_HAL_ChibiOS/RCInput.cpp
+++ b/libraries/AP_HAL_ChibiOS/RCInput.cpp
@@ -214,7 +214,7 @@ void RCInput::_timer_tick(void)
 
 bool RCInput::rc_bind(int dsmMode)
 {
-#if HAL_RCINPUT_WITH_AP_RADIO
+#ifdef HAL_RCINPUT_WITH_AP_RADIO
     if (radio) {
         radio->start_recv_bind();
     }
diff --git a/libraries/AP_HAL_ChibiOS/RCInput.h b/libraries/AP_HAL_ChibiOS/RCInput.h
index 338a5607db..c80e008df5 100644
--- a/libraries/AP_HAL_ChibiOS/RCInput.h
+++ b/libraries/AP_HAL_ChibiOS/RCInput.h
@@ -69,7 +69,7 @@ private:
     uint32_t last_radio_us;
 #endif
 
-#ifdef HAL_USE_ICU
+#if HAL_USE_ICU == TRUE
     ChibiOS::SoftSigReader sig_reader;
     AP_RCProtocol rcin_prot;
 #endif
diff --git a/libraries/AP_HAL_ChibiOS/SoftSigReader.cpp b/libraries/AP_HAL_ChibiOS/SoftSigReader.cpp
index 82a0aea47a..09c980a156 100644
--- a/libraries/AP_HAL_ChibiOS/SoftSigReader.cpp
+++ b/libraries/AP_HAL_ChibiOS/SoftSigReader.cpp
@@ -22,6 +22,8 @@
 using namespace ChibiOS;
 extern const AP_HAL::HAL& hal;
 
+#if HAL_USE_ICU == TRUE
+
 bool SoftSigReader::attach_capture_timer(ICUDriver* icu_drv, icuchannel_t chan, uint8_t dma_stream, uint32_t dma_channel)
 {
     if (chan > ICU_CHANNEL_2) {
@@ -115,5 +117,6 @@ bool SoftSigReader::set_bounce_buf_size(uint16_t buf_size)
     return true;
 }
 
+#endif // HAL_USE_ICU
 
 #endif //CONFIG_HAL_BOARD == HAL_BOARD_CHIBIOS
diff --git a/libraries/AP_HAL_ChibiOS/SoftSigReader.h b/libraries/AP_HAL_ChibiOS/SoftSigReader.h
index c28fe51e12..38788904b6 100644
--- a/libraries/AP_HAL_ChibiOS/SoftSigReader.h
+++ b/libraries/AP_HAL_ChibiOS/SoftSigReader.h
@@ -20,6 +20,8 @@
 
 #include "AP_HAL_ChibiOS.h"
 
+#if HAL_USE_ICU == TRUE
+
 #define INPUT_CAPTURE_FREQUENCY 1000000 //capture unit in microseconds
 #define MAX_SIGNAL_TRANSITIONS 256
 #define DEFAULT_BOUNCE_BUF_SIZE 32
@@ -41,3 +43,6 @@ private:
     ICUConfig icucfg;
     uint16_t _bounce_buf_size = DEFAULT_BOUNCE_BUF_SIZE;
 };
+
+#endif // HAL_USE_ICU
+