diff --git a/src/kernel/unit.h b/src/kernel/unit.h
index cb0ab5f68..907e16e8c 100644
--- a/src/kernel/unit.h
+++ b/src/kernel/unit.h
@@ -28,6 +28,8 @@ extern "C" {
 
   struct skill;
   struct item;
+  struct sc_mage;
+
 #define UFL_DEBUG         (1<<0)
 #define UFL_ISNEW         (1<<1)        /* 2 */
 #define UFL_LONGACTION    (1<<2)        /* 4 */