diff --git a/src/battle_util.c b/src/battle_util.c
index 2e1cbd2d42..ea743e0459 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -5799,6 +5799,22 @@ u32 AbilityBattleEffects(u32 caseID, u32 battler, u32 ability, u32 special, u32
                 effect++;
             }
             break;
+        case ABILITY_TOXIC_CHAIN:
+            if (!(gMoveResultFlags & MOVE_RESULT_NO_EFFECT)
+             && IsBattlerAlive(gBattlerTarget)
+             && !gProtectStructs[gBattlerAttacker].confusionSelfDmg
+             && CanBePoisoned(gBattlerAttacker, gBattlerTarget)
+             && TARGET_TURN_DAMAGED // Need to actually hit the target
+             && (Random() % 3) == 0)
+            {
+                gBattleScripting.moveEffect = MOVE_EFFECT_TOXIC;
+                PREPARE_ABILITY_BUFFER(gBattleTextBuff1, gLastUsedAbility);
+                BattleScriptPushCursor();
+                gBattlescriptCurrInstr = BattleScript_AbilityStatusEffect;
+                gHitMarker |= HITMARKER_STATUS_ABILITY_EFFECT;
+                effect++;
+            }
+            break;
         case ABILITY_STENCH:
             if (!(gMoveResultFlags & MOVE_RESULT_NO_EFFECT)
              && IsBattlerAlive(gBattlerTarget)