diff --git a/libraries/AP_CANManager/AP_CANSensor.cpp b/libraries/AP_CANManager/AP_CANSensor.cpp
index e86ef31992..ffa9bf3cc6 100644
--- a/libraries/AP_CANManager/AP_CANSensor.cpp
+++ b/libraries/AP_CANManager/AP_CANSensor.cpp
@@ -135,7 +135,7 @@ bool CANSensor::add_interface(AP_HAL::CANIface* can_iface)
     return true;
 }
 
-bool CANSensor::write_frame(AP_HAL::CANFrame &out_frame, const uint64_t timeout_us)
+bool CANSensor::write_frame(AP_HAL::CANFrame &out_frame, const uint32_t timeout_us)
 {
     if (!_initialized) {
         debug_can(AP_CANManager::LOG_ERROR, "Driver not initialized for write_frame");
@@ -171,12 +171,12 @@ void CANSensor::loop()
 #endif
 
     while (true) {
-        uint64_t timeout = AP_HAL::micros64() + LOOP_INTERVAL_US;
+        uint64_t deadline_us = AP_HAL::micros64() + LOOP_INTERVAL_US;
 
         // wait to receive frame
         bool read_select = true;
         bool write_select = false;
-        bool ret = _can_iface->select(read_select, write_select, nullptr, timeout);
+        bool ret = _can_iface->select(read_select, write_select, nullptr, deadline_us);
         if (ret && read_select) {
             uint64_t time;
             AP_HAL::CANIface::CanIOFlags flags {};
diff --git a/libraries/AP_CANManager/AP_CANSensor.h b/libraries/AP_CANManager/AP_CANSensor.h
index 7afd1bbea0..b5ac4ee3b0 100644
--- a/libraries/AP_CANManager/AP_CANSensor.h
+++ b/libraries/AP_CANManager/AP_CANSensor.h
@@ -43,7 +43,7 @@ public:
     virtual void handle_frame(AP_HAL::CANFrame &frame) = 0;
 
     // handler for outgoing frames
-    bool write_frame(AP_HAL::CANFrame &out_frame, const uint64_t timeout_us);
+    bool write_frame(AP_HAL::CANFrame &out_frame, const uint32_t timeout_us);
 
 #ifdef HAL_BUILD_AP_PERIPH
     static void set_periph(const uint8_t i, const AP_CAN::Protocol protocol, AP_HAL::CANIface* iface) {