diff --git a/src/modules/px4iofirmware/protocol.h b/src/modules/px4iofirmware/protocol.h
index accd25206f..f61e56d204 100644
--- a/src/modules/px4iofirmware/protocol.h
+++ b/src/modules/px4iofirmware/protocol.h
@@ -93,7 +93,6 @@
 #define PX4IO_P_CONFIG_RC_INPUT_COUNT		6	/* hardcoded max R/C input count supported */
 #define PX4IO_P_CONFIG_ADC_INPUT_COUNT		7	/* hardcoded max ADC inputs */
 #define PX4IO_P_CONFIG_RELAY_COUNT		8	/* hardcoded # of relay outputs */
-#define PX4IO_P_CONFIG_CONTROL_GROUP_COUNT	8	/**< hardcoded # of control groups*/
 
 /* dynamic status page */
 #define PX4IO_PAGE_STATUS		1