diff --git a/dsdl/uavcan/protocol/560.RestartNode.uavcan b/dsdl/uavcan/protocol/560.RestartNode.uavcan
index 7ba6a9e09b..b4f4672da0 100644
--- a/dsdl/uavcan/protocol/560.RestartNode.uavcan
+++ b/dsdl/uavcan/protocol/560.RestartNode.uavcan
@@ -3,8 +3,8 @@
 # Some nodes may require restart before the new configuration will be applied.
 #
 
-uint64 MAGIC_NUMBER = 0xACCE551B1E012345
-uint64 magic_number
+uint40 MAGIC_NUMBER = 0xACCE551B1E
+uint40 magic_number
 
 ---