diff --git a/libraries/AP_DroneCAN/AP_Canard_iface.cpp b/libraries/AP_DroneCAN/AP_Canard_iface.cpp
index 7382f57033..fd38e303c4 100644
--- a/libraries/AP_DroneCAN/AP_Canard_iface.cpp
+++ b/libraries/AP_DroneCAN/AP_Canard_iface.cpp
@@ -456,7 +456,7 @@ bool CanardInterface::add_11bit_driver(CANSensor *sensor)
 }
 
 // handler for outgoing frames for auxillary drivers
-bool CanardInterface::write_aux_frame(AP_HAL::CANFrame &out_frame, const uint64_t timeout_us)
+bool CanardInterface::write_aux_frame(AP_HAL::CANFrame &out_frame, const uint32_t timeout_us)
 {
     const uint64_t tx_deadline_us = AP_HAL::micros64() + timeout_us;
     bool ret = false;
diff --git a/libraries/AP_DroneCAN/AP_Canard_iface.h b/libraries/AP_DroneCAN/AP_Canard_iface.h
index 43d786639f..671722028d 100644
--- a/libraries/AP_DroneCAN/AP_Canard_iface.h
+++ b/libraries/AP_DroneCAN/AP_Canard_iface.h
@@ -54,7 +54,7 @@ public:
     bool add_11bit_driver(CANSensor *sensor);
 
     // handler for outgoing frames for auxillary drivers
-    bool write_aux_frame(AP_HAL::CANFrame &out_frame, const uint64_t timeout_us);
+    bool write_aux_frame(AP_HAL::CANFrame &out_frame, const uint32_t timeout_us);
     
 #if AP_TEST_DRONECAN_DRIVERS
     static CanardInterface& get_test_iface() { return test_iface; }
diff --git a/libraries/AP_DroneCAN/AP_DroneCAN.cpp b/libraries/AP_DroneCAN/AP_DroneCAN.cpp
index 21243e5d08..639e017e82 100644
--- a/libraries/AP_DroneCAN/AP_DroneCAN.cpp
+++ b/libraries/AP_DroneCAN/AP_DroneCAN.cpp
@@ -1956,7 +1956,7 @@ bool AP_DroneCAN::add_11bit_driver(CANSensor *sensor)
 }
 
 // handler for outgoing frames for auxillary drivers
-bool AP_DroneCAN::write_aux_frame(AP_HAL::CANFrame &out_frame, const uint64_t timeout_us)
+bool AP_DroneCAN::write_aux_frame(AP_HAL::CANFrame &out_frame, const uint32_t timeout_us)
 {
     if (out_frame.isExtended()) {
         // don't allow extended frames to be sent by auxillary driver
diff --git a/libraries/AP_DroneCAN/AP_DroneCAN.h b/libraries/AP_DroneCAN/AP_DroneCAN.h
index 2d6e5ae2b7..9a7ae54c66 100644
--- a/libraries/AP_DroneCAN/AP_DroneCAN.h
+++ b/libraries/AP_DroneCAN/AP_DroneCAN.h
@@ -95,7 +95,7 @@ public:
     bool add_11bit_driver(CANSensor *sensor) override;
 
     // handler for outgoing frames for auxillary drivers
-    bool write_aux_frame(AP_HAL::CANFrame &out_frame, const uint64_t timeout_us) override;
+    bool write_aux_frame(AP_HAL::CANFrame &out_frame, const uint32_t timeout_us) override;
     
     uint8_t get_driver_index() const { return _driver_index; }