diff --git a/libraries/AP_SerialManager/AP_SerialManager.cpp b/libraries/AP_SerialManager/AP_SerialManager.cpp
index 87b8ac71e3..73246c51f9 100644
--- a/libraries/AP_SerialManager/AP_SerialManager.cpp
+++ b/libraries/AP_SerialManager/AP_SerialManager.cpp
@@ -225,7 +225,7 @@ const AP_Param::GroupInfo AP_SerialManager::var_info[] = {
     // @Param: 1_OPTIONS
     // @DisplayName: Telem1 options
     // @Description: Control over UART options. The InvertRX option controls invert of the receive pin. The InvertTX option controls invert of the transmit pin. The HalfDuplex option controls half-duplex (onewire) mode, where both transmit and receive is done on the transmit wire. The Swap option allows the RX and TX pins to be swapped on STM32F7 based boards.
-    // @Bitmask: 0:InvertRX, 1:InvertTX, 2:HalfDuplex, 3:Swap, 4: RX_PullDown, 5: RX_PullUp, 6: TX_PullDown, 7: TX_PullUp, 8: RX_NoDMA, 9: TX_NoDMA, 10: Don't forward mavlink to/from, 11: DisableFIFO, 12: Ignore Streamrate
+    // @Bitmask: 0:InvertRX, 1:InvertTX, 2:HalfDuplex, 3:SwapTXRX, 4: RX_PullDown, 5: RX_PullUp, 6: TX_PullDown, 7: TX_PullUp, 8: RX_NoDMA, 9: TX_NoDMA, 10: Don't forward mavlink to/from, 11: DisableFIFO, 12: Ignore Streamrate
     // @User: Advanced
     // @RebootRequired: True
     AP_GROUPINFO("1_OPTIONS",  14, AP_SerialManager, state[1].options, 0),