diff --git a/src/midi_transport.cpp b/src/midi_transport.cpp
index 8276b18..f8490b7 100644
--- a/src/midi_transport.cpp
+++ b/src/midi_transport.cpp
@@ -92,6 +92,7 @@ void UsbMidiTransport::send_note_off(uint8_t channel, uint8_t note, uint8_t velo
 
 void UsbMidiTransport::send_cc(uint8_t channel, uint8_t cc, uint8_t value) {
     if (!initialized) return;
+    if (!TinyUSBDevice.ready()) return;
     uint8_t packet[4] = {0x0B, (uint8_t)(0xB0 | (channel - 1)), cc, value};
     usb_midi.writePacket(packet);
 }