diff --git a/libuavcan/include/uavcan/internal/transport/transfer_receiver.hpp b/libuavcan/include/uavcan/internal/transport/transfer_receiver.hpp
index 750a2475d5..1873587faa 100644
--- a/libuavcan/include/uavcan/internal/transport/transfer_receiver.hpp
+++ b/libuavcan/include/uavcan/internal/transport/transfer_receiver.hpp
@@ -91,7 +91,7 @@ public:
         return *this;
     }
 
-    bool isTimedOut(uint64_t timestamp) const;
+    bool isTimedOut(uint64_t ts_monotonic) const;
 
     ResultCode addFrame(const RxFrame& frame);
 
diff --git a/libuavcan/src/transport/transfer_receiver.cpp b/libuavcan/src/transport/transfer_receiver.cpp
index 34c52f4365..0c7be113bf 100644
--- a/libuavcan/src/transport/transfer_receiver.cpp
+++ b/libuavcan/src/transport/transfer_receiver.cpp
@@ -137,13 +137,13 @@ TransferReceiver::ResultCode TransferReceiver::receive(const RxFrame& frame)
     return RESULT_NOT_COMPLETE;
 }
 
-bool TransferReceiver::isTimedOut(uint64_t timestamp) const
+bool TransferReceiver::isTimedOut(uint64_t ts_monotonic) const
 {
     static const uint64_t INTERVAL_MULT = (1 << TransferID::BITLEN) / 2 - 1;
     const uint64_t ts = this_transfer_ts_monotonic_;
-    if (timestamp <= ts)
+    if (ts_monotonic <= ts)
         return false;
-    return (timestamp - ts) > (uint64_t(transfer_interval_) * INTERVAL_MULT);
+    return (ts_monotonic - ts) > (uint64_t(transfer_interval_) * INTERVAL_MULT);
 }
 
 TransferReceiver::ResultCode TransferReceiver::addFrame(const RxFrame& frame)