diff --git a/include/battle_ai_util.h b/include/battle_ai_util.h
index 304a8149db..b6df2168ea 100644
--- a/include/battle_ai_util.h
+++ b/include/battle_ai_util.h
@@ -54,7 +54,7 @@ bool32 IsRecycleEncouragedItem(u16 item);
 bool32 CanKnockOffItem(u8 battler, u16 item);
 bool32 IsAbilityOfRating(u16 ability, s8 rating);
 s8 GetAbilityRating(u16 ability);
-u32 AI_IsAbilityOnSide(u32 battlerId, u32 ability);
+bool32 AI_IsAbilityOnSide(u32 battlerId, u32 ability);
 
 // stat stage checks
 bool32 AnyStatIsRaised(u8 battlerId);
diff --git a/src/battle_ai_util.c b/src/battle_ai_util.c
index bf10666f60..a080349799 100644
--- a/src/battle_ai_util.c
+++ b/src/battle_ai_util.c
@@ -1065,14 +1065,14 @@ bool32 CanTargetFaintAiWithMod(u8 battlerDef, u8 battlerAtk, s32 hpMod, s32 dmgM
     return FALSE;
 }
 
-u32 AI_IsAbilityOnSide(u32 battlerId, u32 ability)
+bool32 AI_IsAbilityOnSide(u32 battlerId, u32 ability)
 {
     if (IsBattlerAlive(battlerId) && AI_GetAbility(battlerId) == ability)
-        return battlerId + 1;
+        return TRUE;
     else if (IsBattlerAlive(BATTLE_PARTNER(battlerId)) && AI_GetAbility(BATTLE_PARTNER(battlerId)) == ability)
-        return BATTLE_PARTNER(battlerId) + 1;
+        return TRUE;
     else
-        return 0;
+        return FALSE;
 }
 
 // does NOT include ability suppression checks