diff --git a/src/battle_ai_switch_items.c b/src/battle_ai_switch_items.c
index fe3bb5a5ed..d6ac5d025e 100644
--- a/src/battle_ai_switch_items.c
+++ b/src/battle_ai_switch_items.c
@@ -1444,33 +1444,18 @@ static u32 GetBestMonBatonPass(struct Pokemon *party, int firstId, int lastId, u
 static u32 GetBestMonTypeMatchup(struct Pokemon *party, int firstId, int lastId, u8 invalidMons, u32 battler, u32 opposingBattler)
 {
     int i, bits = 0;
-
     while (bits != 0x3F) // All mons were checked.
     {
-        uq4_12_t bestResist = UQ_4_12(1.0);
+        u32 bestResist = UQ_4_12(2.0);
         int bestMonId = PARTY_SIZE;
         // Find the mon whose type is the most suitable defensively.
         for (i = firstId; i < lastId; i++)
         {
             if (!((1u << i) & invalidMons) && !((1u << i) & bits))
             {
-                u16 species = GetMonData(&party[i], MON_DATA_SPECIES);
-                uq4_12_t typeEffectiveness = UQ_4_12(1.0);
+                InitializeSwitchinCandidate(&party[i]);
 
-                u8 atkType1 = gBattleMons[opposingBattler].types[0];
-                u8 atkType2 = gBattleMons[opposingBattler].types[1];
-                u8 defType1 = GetSpeciesType(species, 0);
-                u8 defType2 = GetSpeciesType(species, 1);
-
-                typeEffectiveness = uq4_12_multiply(typeEffectiveness, (GetTypeModifier(atkType1, defType1)));
-                if (atkType2 != atkType1)
-                    typeEffectiveness = uq4_12_multiply(typeEffectiveness, (GetTypeModifier(atkType2, defType1)));
-                if (defType2 != defType1)
-                {
-                    typeEffectiveness = uq4_12_multiply(typeEffectiveness, (GetTypeModifier(atkType1, defType2)));
-                    if (atkType2 != atkType1)
-                        typeEffectiveness = uq4_12_multiply(typeEffectiveness, (GetTypeModifier(atkType2, defType2)));
-                }
+                u32 typeEffectiveness = GetBattleMonTypeMatchup(gBattleMons[opposingBattler], gAiLogicData->switchinCandidate.battleMon);
                 if (typeEffectiveness < bestResist)
                 {
                     bestResist = typeEffectiveness;
diff --git a/test/battle/ai/ai_switching.c b/test/battle/ai/ai_switching.c
index 45b50b7638..a858c33ded 100644
--- a/test/battle/ai/ai_switching.c
+++ b/test/battle/ai/ai_switching.c
@@ -1316,6 +1316,21 @@ AI_SINGLE_BATTLE_TEST("AI_FLAG_SMART_MON_CHOICES: AI will properly consider immu
     }
 }
 
+AI_DOUBLE_BATTLE_TEST("AI_FLAG_SMART_MON_CHOICES: AI will properly consider immunities when determining switchin type matchup (Doubles)")
+{
+    GIVEN {
+        AI_FLAGS(AI_FLAG_CHECK_BAD_MOVE | AI_FLAG_CHECK_VIABILITY | AI_FLAG_TRY_TO_FAINT | AI_FLAG_SMART_MON_CHOICES | AI_FLAG_OMNISCIENT);
+        PLAYER(SPECIES_POLIWRATH) { Moves(MOVE_WATER_GUN, MOVE_KARATE_CHOP); }
+        PLAYER(SPECIES_ZIGZAGOON) { Moves(MOVE_CELEBRATE); }
+        OPPONENT(SPECIES_ZIGZAGOON) { Level(1); Moves(MOVE_CELEBRATE); }
+        OPPONENT(SPECIES_ZIGZAGOON) { Level(1); Moves(MOVE_CELEBRATE); }
+        OPPONENT(SPECIES_CERULEDGE) { Moves(MOVE_SPARK); }
+        OPPONENT(SPECIES_WHIMSICOTT) { Moves(MOVE_MEGA_DRAIN); }
+    } WHEN {
+        TURN { MOVE(playerLeft, MOVE_KARATE_CHOP, target:opponentLeft); MOVE(playerRight, MOVE_CELEBRATE); EXPECT_MOVE(opponentLeft, MOVE_CELEBRATE); EXPECT_MOVE(opponentRight, MOVE_CELEBRATE); EXPECT_SEND_OUT(opponentLeft, 3); }
+    }
+}
+
 AI_SINGLE_BATTLE_TEST("AI_FLAG_SMART_SWITCHING: AI won't switch out due to bad odds if it can OHKO with a priority move")
 {
     PASSES_RANDOMLY(100, 100, RNG_AI_SWITCH_HASBADODDS);