diff --git a/data/battle_scripts_1.s b/data/battle_scripts_1.s
index 43f961f35f..65e2598964 100644
--- a/data/battle_scripts_1.s
+++ b/data/battle_scripts_1.s
@@ -367,8 +367,13 @@ gBattleScriptsForMoveEffects:: @ 82D86A8
 	.4byte BattleScript_EffectFairyLock
 	.4byte BattleScript_EffectAllySwitch
 	.4byte BattleScript_EffectSleepHit
+	.4byte BattleScript_EffectAttackerDefenseDownHit
 	.4byte BattleScript_EffectBodyPress
 
+BattleScript_EffectAttackerDefenseDownHit:
+	setmoveeffect MOVE_EFFECT_DEF_MINUS_1 | MOVE_EFFECT_AFFECTS_USER | MOVE_EFFECT_CERTAIN
+	goto BattleScript_EffectHit
+
 BattleScript_EffectSleepHit:
 	setmoveeffect MOVE_EFFECT_SLEEP
 	goto BattleScript_EffectHit
diff --git a/include/constants/battle_move_effects.h b/include/constants/battle_move_effects.h
index 4c5ada890b..6174ca4968 100644
--- a/include/constants/battle_move_effects.h
+++ b/include/constants/battle_move_effects.h
@@ -351,8 +351,9 @@
 #define EFFECT_FAIRY_LOCK 345
 #define EFFECT_ALLY_SWITCH 346
 #define EFFECT_SLEEP_HIT 347 // Relic Song
-#define EFFECT_BODY_PRESS 348
+#define EFFECT_ATTACKER_DEFENSE_DOWN_HIT 348
+#define EFFECT_BODY_PRESS 349
 
-#define NUM_BATTLE_MOVE_EFFECTS 349
+#define NUM_BATTLE_MOVE_EFFECTS 350
 
 #endif  // GUARD_CONSTANTS_BATTLE_MOVE_EFFECTS_H
diff --git a/src/data/battle_moves.h b/src/data/battle_moves.h
index 95e6ec4846..d6e3a80169 100644
--- a/src/data/battle_moves.h
+++ b/src/data/battle_moves.h
@@ -10141,12 +10141,12 @@ const struct BattleMove gBattleMoves[MOVES_COUNT] =
 
     [MOVE_CLANGING_SCALES] =
     {
-        .effect = EFFECT_DEFENSE_DOWN_HIT,
+        .effect = EFFECT_ATTACKER_DEFENSE_DOWN_HIT,
         .power = 110,
         .type = TYPE_DRAGON,
         .accuracy = 100,
         .pp = 5,
-        .secondaryEffectChance = 100,
+        .secondaryEffectChance = 0,
         .target = MOVE_TARGET_SELECTED,
         .priority = 0,
         .flags = FLAG_PROTECT_AFFECTED | FLAG_MIRROR_MOVE_AFFECTED | FLAG_KINGS_ROCK_AFFECTED | FLAG_SOUND,