diff --git a/src/battle_ai_switch_items.c b/src/battle_ai_switch_items.c
index aa7d819a1e..9c8061aabf 100644
--- a/src/battle_ai_switch_items.c
+++ b/src/battle_ai_switch_items.c
@@ -1507,6 +1507,24 @@ static u32 GetBestMonDmg(struct Pokemon *party, int firstId, int lastId, u8 inva
     return bestMonId;
 }
 
+static u32 GetFirstNonIvalidMon(u32 firstId, u32 lastId, u32 invalidMons, u32 battlerIn1, u32 battlerIn2)
+{
+    if (!IsDoubleBattle())
+        return PARTY_SIZE;
+
+    if (PARTY_SIZE != gBattleStruct->monToSwitchIntoId[battlerIn1]
+     && PARTY_SIZE != gBattleStruct->monToSwitchIntoId[battlerIn2])
+        return PARTY_SIZE;
+
+    for (u32 chosenMonId = (lastId-1); chosenMonId >= firstId; chosenMonId--)
+    {
+        if ((1 << (chosenMonId)) & invalidMons)
+            continue;
+        return chosenMonId; // first non invalid mon found
+    }
+    return PARTY_SIZE;
+}
+
 bool32 IsMonGrounded(u16 heldItemEffect, u32 ability, u8 type1, u8 type2)
 {
     // List that makes mon not grounded
@@ -2045,6 +2063,7 @@ static u32 GetBestMonIntegrated(struct Pokemon *party, int firstId, int lastId,
     u32 aiMove, hitsToKOAI, maxHitsToKO = 0;
     u16 bestResist = UQ_4_12(1.0), bestResistEffective = UQ_4_12(1.0), typeMatchup;
     bool32 isFreeSwitch = IsFreeSwitch(switchType, battlerIn1, opposingBattler), isSwitchinFirst, canSwitchinWin1v1;
+    u32 invalidMons = 0;
 
     // Iterate through mons
     for (i = firstId; i < lastId; i++)
@@ -2056,6 +2075,7 @@ static u32 GetBestMonIntegrated(struct Pokemon *party, int firstId, int lastId,
             || i == gBattleStruct->monToSwitchIntoId[battlerIn1]
             || i == gBattleStruct->monToSwitchIntoId[battlerIn2])
         {
+            invalidMons |= 1u << i;
             continue;
         }
         // Save Ace Pokemon for last
@@ -2063,6 +2083,7 @@ static u32 GetBestMonIntegrated(struct Pokemon *party, int firstId, int lastId,
         {
             aceMonId = i;
             aceMonCount++;
+            invalidMons |= 1u << i;
             continue;
         }
         else
@@ -2212,6 +2233,11 @@ static u32 GetBestMonIntegrated(struct Pokemon *party, int firstId, int lastId,
      && (IsSwitchOutEffect(GetMoveEffect(gCurrentMove)) || gAiLogicData->ejectButtonSwitch || gAiLogicData->ejectPackSwitch))
         return aceMonId;
 
+    // Fallback
+    u32 bestMonId = GetFirstNonIvalidMon(firstId, lastId, invalidMons, battlerIn1, battlerIn2);
+    if (bestMonId != PARTY_SIZE)
+        return bestMonId;
+
     return PARTY_SIZE;
 }
 
@@ -2329,6 +2355,11 @@ u32 GetMostSuitableMonToSwitchInto(u32 battler, enum SwitchType switchType)
         && (IsSwitchOutEffect(GetMoveEffect(gCurrentMove)) || gAiLogicData->ejectButtonSwitch || gAiLogicData->ejectPackSwitch))
             return aceMonId;
 
+        // Fallback
+        bestMonId = GetFirstNonIvalidMon(firstId, lastId, invalidMons, battlerIn1, battlerIn2);
+        if (bestMonId != PARTY_SIZE)
+            return bestMonId;
+
         return PARTY_SIZE;
     }
 }