diff --git a/src/drivers/uavcan/libdronecan/libuavcan/include/uavcan/transport/can_io.hpp b/src/drivers/uavcan/libdronecan/libuavcan/include/uavcan/transport/can_io.hpp
index 144c246bc4e..e33f703c299 100644
--- a/src/drivers/uavcan/libdronecan/libuavcan/include/uavcan/transport/can_io.hpp
+++ b/src/drivers/uavcan/libdronecan/libuavcan/include/uavcan/transport/can_io.hpp
@@ -117,6 +117,8 @@ public:
     /// The 'or equal' condition is necessary to avoid frame reordering.
     bool topPriorityHigherOrEqual(const CanFrame& rhs_frame) const;
 
+    /// Total. Every drop is also counted in exactly one of the two below, so a total that exceeds
+    /// their sum means a drop path was added without classifying it.
     uint32_t getRejectedFrameCount() const { return rejected_frames_cnt_; }
 
     /// Frames dropped because their transmit deadline had already passed. Not a memory shortage.
diff --git a/src/drivers/uavcan/libdronecan/libuavcan/src/transport/uc_can_io.cpp b/src/drivers/uavcan/libdronecan/libuavcan/src/transport/uc_can_io.cpp
index cb310bb6c84..1ca5b8700e8 100644
--- a/src/drivers/uavcan/libdronecan/libuavcan/src/transport/uc_can_io.cpp
+++ b/src/drivers/uavcan/libdronecan/libuavcan/src/transport/uc_can_io.cpp
@@ -207,7 +207,7 @@ CanTxQueue::Entry* CanTxQueue::peek()
         {
             UAVCAN_TRACE("CanTxQueue", "Peek: Expired %s", p->toString().c_str());
             Entry* const next = p->getNextListNode();
-            registerRejectedFrame();
+            registerExpiredFrame();
             remove(p);
             p = next;
         }