diff --git a/libraries/AP_IOMCU/AP_IOMCU.cpp b/libraries/AP_IOMCU/AP_IOMCU.cpp
index cd519d982f..d89d7bc2b2 100644
--- a/libraries/AP_IOMCU/AP_IOMCU.cpp
+++ b/libraries/AP_IOMCU/AP_IOMCU.cpp
@@ -389,10 +389,7 @@ void AP_IOMCU::read_servo()
  */
 void AP_IOMCU::discard_input(void)
 {
-    uint32_t n = uart.available();
-    while (n--) {
-        uart.read();
-    }
+    uart.discard_input();
 }
 
 /*