diff --git a/common/main/multi.h b/common/main/multi.h
index aff0e07b3..fd51625ca 100644
--- a/common/main/multi.h
+++ b/common/main/multi.h
@@ -497,7 +497,6 @@ static inline void multi_send_endlevel_start(bool secret)
 }
 #endif
 void multi_send_player_deres(deres_type_t type);
-void multi_send_message(void);
 void multi_send_reappear();
 void multi_send_create_explosion(playernum_t);
 void multi_send_controlcen_fire(const vms_vector &to_target, int gun_num, objnum_t objnum);
diff --git a/similar/main/multi.cpp b/similar/main/multi.cpp
index 692024e5a..99aad9a0e 100644
--- a/similar/main/multi.cpp
+++ b/similar/main/multi.cpp
@@ -109,6 +109,7 @@ static void multi_send_quit();
 static void multi_process_data(playernum_t pnum, const ubyte *dat, uint_fast32_t type);
 static playernum_t multi_who_is_master();
 static void multi_show_player_list();
+static void multi_send_message();
 
 #if !(!defined(RELEASE) && defined(DXX_BUILD_DESCENT_II))
 static void multi_add_lifetime_kills(int count);