diff --git a/src/mon.c b/src/mon.c
index 07db84520..37645ebc7 100644
--- a/src/mon.c
+++ b/src/mon.c
@@ -1368,7 +1368,7 @@ register struct monst *mon;
 	}
 }
 
-void
+STATIC_OVL void
 dealloc_mextra(x)
 struct mextra *x;
 {