diff --git a/src/main/fc/fc_msp.c b/src/main/fc/fc_msp.c
index d00984f2d85..b241c0df69b 100644
--- a/src/main/fc/fc_msp.c
+++ b/src/main/fc/fc_msp.c
@@ -223,7 +223,13 @@ static void mspSerialPassthroughFn(serialPort_t *serialPort)
 {
     serialPort_t *passthroughPort = mspFindPassthroughSerialPort();
     if (passthroughPort && serialPort) {
-        serialPassthrough(passthroughPort, serialPort, NULL, NULL);
+        // The port the request came in on goes first, as it does in the CLI. Both of the
+        // things serialPassthrough() does for whoever opened the session are done for its
+        // first port only: the +++ that ends the session is looked for there, and a USB
+        // host's line coding is mirrored onto the other port from there. Passed the other
+        // way round, a session opened over MSP could not be closed and could not raise the
+        // rate of the port it opened, which is what an SRXL2 ESC negotiates up to 400000
+        serialPassthrough(serialPort, passthroughPort, NULL, NULL);
     }
 }