diff --git a/libraries/AP_Radio/AP_Radio_cc2500.cpp b/libraries/AP_Radio/AP_Radio_cc2500.cpp
index e5e3b443af..fd6fc0a676 100644
--- a/libraries/AP_Radio/AP_Radio_cc2500.cpp
+++ b/libraries/AP_Radio/AP_Radio_cc2500.cpp
@@ -414,7 +414,7 @@ void AP_Radio_cc2500::trigger_irq_radio_event()
     chSysUnlockFromISR();
 }
 
-void AP_Radio_cc2500::trigger_timeout_event(void *arg)
+void AP_Radio_cc2500::trigger_timeout_event(virtual_timer_t* vt, void *arg)
 {
     (void)arg;
     //we are called from ISR context
diff --git a/libraries/AP_Radio/AP_Radio_cc2500.h b/libraries/AP_Radio/AP_Radio_cc2500.h
index ce5feb0c1f..1ddc608173 100644
--- a/libraries/AP_Radio/AP_Radio_cc2500.h
+++ b/libraries/AP_Radio/AP_Radio_cc2500.h
@@ -87,7 +87,7 @@ private:
 
     static void irq_handler_thd(void* arg);
     static void trigger_irq_radio_event(void);
-    static void trigger_timeout_event(void *arg);
+    static void trigger_timeout_event(virtual_timer_t* vt, void *arg);
 
     void radio_init(void);
 
diff --git a/libraries/AP_Radio/AP_Radio_cypress.cpp b/libraries/AP_Radio/AP_Radio_cypress.cpp
index a66de15358..ff6f99b4b6 100644
--- a/libraries/AP_Radio/AP_Radio_cypress.cpp
+++ b/libraries/AP_Radio/AP_Radio_cypress.cpp
@@ -1199,7 +1199,7 @@ void AP_Radio_cypress::irq_handler_thd(void *arg)
     }
 }
 
-void AP_Radio_cypress::trigger_timeout_event(void *arg)
+void AP_Radio_cypress::trigger_timeout_event(virtual_timer_t* vt, void *arg)
 {
     (void)arg;
     //we are called from ISR context
diff --git a/libraries/AP_Radio/AP_Radio_cypress.h b/libraries/AP_Radio/AP_Radio_cypress.h
index 7aa49f615a..15c63d528d 100644
--- a/libraries/AP_Radio/AP_Radio_cypress.h
+++ b/libraries/AP_Radio/AP_Radio_cypress.h
@@ -131,7 +131,7 @@ private:
 
     static void irq_handler_thd(void* arg);
     static void trigger_irq_radio_event(void);
-    static void trigger_timeout_event(void *arg);
+    static void trigger_timeout_event(virtual_timer_t* vt, void *arg);
 
     static const uint8_t max_channels = 16;