diff --git a/libuavcan/include/uavcan/can_driver.hpp b/libuavcan/include/uavcan/can_driver.hpp
index 3f3570326a..367b28cc23 100644
--- a/libuavcan/include/uavcan/can_driver.hpp
+++ b/libuavcan/include/uavcan/can_driver.hpp
@@ -9,6 +9,7 @@
 #include <stdint.h>
 #include <algorithm>
 #include <string>
+#include <uavcan/internal/impl_constants.hpp>
 
 namespace uavcan
 {