diff --git a/src/drivers/px4io/px4io.cpp b/src/drivers/px4io/px4io.cpp
index 4248900cc6..12ab205c69 100644
--- a/src/drivers/px4io/px4io.cpp
+++ b/src/drivers/px4io/px4io.cpp
@@ -1753,6 +1753,7 @@ Output driver communicating with the IO co-processor.
 	PRINT_MODULE_USAGE_ARG("dsm2|dsmx|dsmx8", "protocol", false);
 	PRINT_MODULE_USAGE_COMMAND_DESCR("sbus1_out", "enable sbus1 out");
 	PRINT_MODULE_USAGE_COMMAND_DESCR("sbus2_out", "enable sbus2 out");
+	PRINT_MODULE_USAGE_COMMAND_DESCR("supported", "Returns 0 if px4io is supported");
 	PRINT_MODULE_USAGE_COMMAND_DESCR("test_fmu_fail", "test: turn off IO updates");
 	PRINT_MODULE_USAGE_COMMAND_DESCR("test_fmu_ok", "re-enable IO updates");