diff --git a/libuavcan/src/transport/uc_frame.cpp b/libuavcan/src/transport/uc_frame.cpp
index 944bd8871e..6d49fec0db 100644
--- a/libuavcan/src/transport/uc_frame.cpp
+++ b/libuavcan/src/transport/uc_frame.cpp
@@ -155,10 +155,13 @@ bool Frame::compile(CanFrame& out_can_frame) const
         tail |= (1U << 5);
     }
 
+    UAVCAN_ASSERT(payload_len_ < sizeof(static_cast<CanFrame*>(NULL)->data));
+
     out_can_frame.dlc = static_cast<uint8_t>(payload_len_);
     (void)copy(payload_, payload_ + payload_len_, out_can_frame.data);
 
     out_can_frame.data[out_can_frame.dlc] = tail;
+    out_can_frame.dlc++;
 
     /*
      * Discriminator