diff --git a/include/constants/pokemon.h b/include/constants/pokemon.h
index 94a2adfcd..d11ae9391 100644
--- a/include/constants/pokemon.h
+++ b/include/constants/pokemon.h
@@ -314,6 +314,7 @@
 #define FLAG_DANCE                  (1 << 21)
 #define FLAG_DMG_IN_AIR             (1 << 22) // X2 dmg on air, always hits target on air
 #define FLAG_HIT_IN_AIR             (1 << 23) // dmg is normal, always hits target on air
+#define FLAG_DAMAGE_AIRBORNE        (1 << 24) // Makes a Ground type move do 1x damage to flying and levitating targets
 
 // Split defines.
 #define SPLIT_PHYSICAL  0x0
diff --git a/src/battle_util.c b/src/battle_util.c
index 0fe791c95..07c150066 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -7961,7 +7961,7 @@ static u16 CalcTypeEffectivenessMultiplierInternal(u16 move, u8 moveType, u8 bat
         && gBattleMons[battlerDef].type3 != gBattleMons[battlerDef].type1)
         MulByTypeEffectiveness(&modifier, move, moveType, battlerDef, gBattleMons[battlerDef].type3, battlerAtk, recordAbilities);
 
-    if (moveType == TYPE_GROUND && !IsBattlerGrounded(battlerDef))
+    if (moveType == TYPE_GROUND && !IsBattlerGrounded(battlerDef) && !(gBattleMoves[move].flags & FLAG_DAMAGE_AIRBORNE))
     {
         modifier = UQ_4_12(0.0);
         if (recordAbilities && GetBattlerAbility(battlerDef) == ABILITY_LEVITATE)
@@ -7973,6 +7973,14 @@ static u16 CalcTypeEffectivenessMultiplierInternal(u16 move, u8 moveType, u8 bat
             RecordAbilityBattle(battlerDef, ABILITY_LEVITATE);
         }
     }
+
+    // Thousand Arrows ignores type modifiers for flying mons
+    if (!IsBattlerGrounded(battlerDef) && (gBattleMoves[move].flags & FLAG_DAMAGE_AIRBORNE)
+        && (gBattleMons[battlerDef].type1 == TYPE_FLYING || gBattleMons[battlerDef].type2 == TYPE_FLYING || gBattleMons[battlerDef].type3 == TYPE_FLYING))
+    {
+        modifier = UQ_4_12(1.0);
+    }
+
     if (GetBattlerAbility(battlerDef) == ABILITY_WONDER_GUARD && modifier <= UQ_4_12(1.0) && gBattleMoves[move].power)
     {
         modifier = UQ_4_12(0.0);
diff --git a/src/data/battle_moves.h b/src/data/battle_moves.h
index c8203aa0e..61050e44f 100644
--- a/src/data/battle_moves.h
+++ b/src/data/battle_moves.h
@@ -9488,10 +9488,10 @@ const struct BattleMove gBattleMoves[MOVES_COUNT] =
         .type = TYPE_GROUND,
         .accuracy = 100,
         .pp = 10,
-        .secondaryEffectChance = 0,
+        .secondaryEffectChance = 100,
         .target = MOVE_TARGET_BOTH,
         .priority = 0,
-        .flags = FLAG_PROTECT_AFFECTED | FLAG_MIRROR_MOVE_AFFECTED | FLAG_KINGS_ROCK_AFFECTED | FLAG_HIT_IN_AIR,
+        .flags = FLAG_PROTECT_AFFECTED | FLAG_MIRROR_MOVE_AFFECTED | FLAG_KINGS_ROCK_AFFECTED | FLAG_HIT_IN_AIR | FLAG_DAMAGE_AIRBORNE,
         .split = SPLIT_PHYSICAL,
     },