diff --git a/firmware/pm.h b/firmware/pm.h
index d4ed08b..105275f 100644
--- a/firmware/pm.h
+++ b/firmware/pm.h
@@ -3,5 +3,6 @@
 #include <avr/io.h>
 
 void suspend();
+char* post();
 
 #endif // PM_H