diff --git a/libraries/AP_UAVCAN/AP_UAVCAN_DNA_Server.cpp b/libraries/AP_UAVCAN/AP_UAVCAN_DNA_Server.cpp
index 45be963c3d..749ef0e2b8 100644
--- a/libraries/AP_UAVCAN/AP_UAVCAN_DNA_Server.cpp
+++ b/libraries/AP_UAVCAN/AP_UAVCAN_DNA_Server.cpp
@@ -633,9 +633,13 @@ void AP_UAVCAN_DNA_Server::handleAllocation(uint8_t driver_index, uint8_t node_i
     }
 
     if (rcvd_unique_id_offset) {
-        debug_uavcan(AP_CANManager::LOG_DEBUG, "TIME: %ld  -- Accepting Followup part! %u\n", uavcan::SystemClock::instance().getMonotonic().toUSec()/1000, (now - last_alloc_msg_ms));
+        debug_uavcan(AP_CANManager::LOG_DEBUG, "TIME: %ld  -- Accepting Followup part! %u\n",
+                     long(uavcan::SystemClock::instance().getMonotonic().toUSec()/1000),
+                     unsigned((now - last_alloc_msg_ms)));
     } else {
-        debug_uavcan(AP_CANManager::LOG_DEBUG, "TIME: %ld  -- Accepting First part! %u\n", uavcan::SystemClock::instance().getMonotonic().toUSec()/1000, (now - last_alloc_msg_ms));
+        debug_uavcan(AP_CANManager::LOG_DEBUG, "TIME: %ld  -- Accepting First part! %u\n",
+                     long(uavcan::SystemClock::instance().getMonotonic().toUSec()/1000),
+                     unsigned((now - last_alloc_msg_ms)));
     }
 
     last_alloc_msg_ms = now;
diff --git a/libraries/AP_UAVCAN/AP_UAVCAN_IfaceMgr.cpp b/libraries/AP_UAVCAN/AP_UAVCAN_IfaceMgr.cpp
index e462a2e3fd..56c1cdfccd 100644
--- a/libraries/AP_UAVCAN/AP_UAVCAN_IfaceMgr.cpp
+++ b/libraries/AP_UAVCAN/AP_UAVCAN_IfaceMgr.cpp
@@ -166,7 +166,7 @@ bool CanIfaceMgr::add_interface(AP_HAL::CANIface *can_iface)
         AP::can().log_text(AP_CANManager::LOG_ERROR, LOG_TAG, "UAVCANIfaceMgr: Setting event handle failed\n");
         return false;
     }
-    AP::can().log_text(AP_CANManager::LOG_INFO, LOG_TAG, "UAVCANIfaceMgr: Successfully added interface %d\n");
+    AP::can().log_text(AP_CANManager::LOG_INFO, LOG_TAG, "UAVCANIfaceMgr: Successfully added interface %d\n", int(num_ifaces));
     num_ifaces++;
     return true;
 }