diff --git a/libuavcan/src/transport/frame.cpp b/libuavcan/src/transport/frame.cpp
index 49fbebed9e..db97f4ce0c 100644
--- a/libuavcan/src/transport/frame.cpp
+++ b/libuavcan/src/transport/frame.cpp
@@ -211,7 +211,14 @@ std::string Frame::toString() const
 bool RxFrame::parse(const CanRxFrame& can_frame)
 {
     if (!Frame::parse(can_frame))
+    {
         return false;
+    }
+    if (can_frame.ts_mono.isZero())  // Monotonic timestamps are mandatory.
+    {
+        assert(0);                   // If it is not set, it's a driver failure.
+        return false;
+    }
     ts_mono_ = can_frame.ts_mono;
     ts_utc_ = can_frame.ts_utc;
     iface_index_ = can_frame.iface_index;
diff --git a/libuavcan/test/transport/frame.cpp b/libuavcan/test/transport/frame.cpp
index b163ceebaa..5435e72fb1 100644
--- a/libuavcan/test/transport/frame.cpp
+++ b/libuavcan/test/transport/frame.cpp
@@ -178,6 +178,7 @@ TEST(Frame, RxFrameParse)
     ASSERT_FALSE(rx_frame.parse(can_rx_frame));
 
     // Valid
+    can_rx_frame.ts_mono = uavcan::MonotonicTime::fromUSec(1);  // Zero is not allowed
     can_rx_frame.id = CanFrame::FlagEFF |
         (2 << 0)   |      //    Transfer ID
         (1 << 3)   |      //    Last Frame
@@ -187,7 +188,7 @@ TEST(Frame, RxFrameParse)
         (456 << 19);      //    Data Type ID
 
     ASSERT_TRUE(rx_frame.parse(can_rx_frame));
-    ASSERT_EQ(0, rx_frame.getMonotonicTimestamp().toUSec());
+    ASSERT_EQ(1, rx_frame.getMonotonicTimestamp().toUSec());
     ASSERT_EQ(0, rx_frame.getIfaceIndex());
 
     can_rx_frame.ts_mono = tsMono(123);