diff --git a/src/battle_terastal.c b/src/battle_terastal.c
index 2c140414db..0c29d20f27 100644
--- a/src/battle_terastal.c
+++ b/src/battle_terastal.c
@@ -62,7 +62,10 @@ void ApplyBattlerVisualsForTeraAnim(u32 battler)
 bool32 CanTerastallize(u32 battler)
 {
     u32 holdEffect = GetBattlerHoldEffect(battler, FALSE);
-
+    
+    if (gBattleMons[battler].status2 & STATUS2_TRANSFORMED && GET_BASE_SPECIES_ID(gBattleMons[battler].species) == SPECIES_TERAPAGOS)
+        return FALSE;
+    
     // Prevents Zigzagoon from terastalizing in vanilla.
     if (gBattleTypeFlags & BATTLE_TYPE_FIRST_BATTLE && GetBattlerSide(battler) == B_SIDE_OPPONENT)
         return FALSE;