diff --git a/main.h b/main.h
index 0f990ea5..f7822513 100644
--- a/main.h
+++ b/main.h
@@ -241,6 +241,8 @@ int groundCommandCount = 0;
     int m_ileaver_index;               /* Byte counter for interleaver */
     unsigned char m_conv_sr;           /* Convolutional encoder shift register state */
 
+void sensor_setup();  // defined in sensor_extension.c
+void sensor_loop();  // defined in sensor_extension.c
 
 // from funcubeLib/common/fecConstants.h