diff --git a/clients/lcdproc/chrono.h b/clients/lcdproc/chrono.h
index ab6b161..02c63b4 100644
--- a/clients/lcdproc/chrono.h
+++ b/clients/lcdproc/chrono.h
@@ -5,5 +5,6 @@ int clock_screen (int rep, int display);
 int uptime_screen (int rep, int display);
 int time_screen (int rep, int display);
 int big_clock_screen (int rep, int display);
+int essential_clock_screen (int rep, int display);
 
 #endif