diff --git a/src/battle_message.c b/src/battle_message.c
index 039aca722..ee0cf63e4 100644
--- a/src/battle_message.c
+++ b/src/battle_message.c
@@ -26,6 +26,7 @@
 #include "constants/frontier_util.h"
 #include "constants/items.h"
 #include "constants/moves.h"
+#include "constants/opponents.h"
 #include "constants/species.h"
 #include "constants/trainers.h"
 #include "constants/trainer_hill.h"
@@ -3878,7 +3879,15 @@ struct TrainerSlide
 
 static const struct TrainerSlide sTrainerSlides[] =
 {
-    {0x291, sText_AarghAlmostHadIt, sText_BoxIsFull, sText_123Poof},
+    /* Put any trainer slide-in messages inside this array.
+    Example:
+    {
+        .trainerId = TRAINER_WALLY_VR_2,
+        .msgLastSwitchIn = sText_AarghAlmostHadIt,
+        .msgLastLowHp = sText_BoxIsFull,
+        .msgFirstDown = sText_123Poof,
+    },
+    */
 };
 
 static u32 GetEnemyMonCount(bool32 onlyAlive)