diff --git a/main.h b/main.h
index 95cbbf59..0ba9c824 100644
--- a/main.h
+++ b/main.h
@@ -247,6 +247,7 @@ int groundCommandCount = 0;
 
 void sensor_setup();  // defined in sensor_extension.c
 int sensor_loop(char *sensor_buffer);  // defined in sensor_extension.c
+int pi_sensors(char *buffer); // used to read BME and MPU sensor if connected to Pi
 
 // from funcubeLib/common/fecConstants.h