diff --git a/code/modules/mob/living/silicon/silicon.dm b/code/modules/mob/living/silicon/silicon.dm
index 68b6aab5c6e..3e053b80af7 100644
--- a/code/modules/mob/living/silicon/silicon.dm
+++ b/code/modules/mob/living/silicon/silicon.dm
@@ -310,7 +310,7 @@
 	else	//For department channels, if any, given by the internal radio.
 		for(var/key in GLOB.department_radio_keys)
 			if(GLOB.department_radio_keys[key] == Autochan)
-				radiomod = key
+				radiomod = ":" + key
 				break
 
 	to_chat(src, "<span class='notice'>Automatic announcements [Autochan == "None" ? "will not use the radio." : "set to [Autochan]."]</span>")