diff --git a/data/uking_functions.csv b/data/uking_functions.csv
index 390b92ce2..d9ae4a8ec 100644
--- a/data/uking_functions.csv
+++ b/data/uking_functions.csv
@@ -74874,7 +74874,7 @@ Address,Quality,Size,Name
 0x0000007100d68ad4,U,000088,
 0x0000007100d68b2c,U,000048,LifeRecoverInfo::onApplyDamage_0
 0x0000007100d68b5c,U,000420,
-0x0000007100d68d00,U,000084,_ZN4ksys3act15LifeRecoverInfo13onApplyDamageERi
+0x0000007100d68d00,O,000084,_ZN4ksys3act15LifeRecoverInfo13onApplyDamageERi
 0x0000007100d68d54,U,000064,
 0x0000007100d68d94,U,000192,printLifeRecoverInfo
 0x0000007100d68e54,U,000188,
diff --git a/src/Game/DLC/aocManager.cpp b/src/Game/DLC/aocManager.cpp
index bb7ca50cb..84e654fa0 100644
--- a/src/Game/DLC/aocManager.cpp
+++ b/src/Game/DLC/aocManager.cpp
@@ -1,8 +1,11 @@
 #include "Game/DLC/aocManager.h"
+#include <algorithm>
 #include <container/seadBuffer.h>
 #include <filedevice/seadFileDeviceMgr.h>
+#include <math/seadMathCalcCommon.h>
 #include <prim/seadStringBuilder.h>
 #include <resource/seadSharcArchiveRes.h>
+#include "KingSystem/ActorSystem/actLifeRecoveryInfo.h"
 #include "KingSystem/Resource/resLoadRequest.h"
 #include "KingSystem/Resource/resResourceMgrTask.h"
 #include "KingSystem/Utils/InitTimeInfo.h"
@@ -15,6 +18,21 @@
 #include <prim/seadStringUtil.h>
 #endif
 
+namespace ksys::act {
+
+bool LifeRecoverInfo::onApplyDamage(s32& damage) {
+    if (mExtraHp1 == 0)
+        return damage > 0;
+
+    const auto previous_extra_hp = mExtraHp1;
+    const auto remaining_extra_hp = std::max(previous_extra_hp - damage, 0);
+    damage -= previous_extra_hp - remaining_extra_hp;
+    mExtraHp1 = sead::Mathf::clampMax(remaining_extra_hp, mExtraHp2);
+    return remaining_extra_hp != previous_extra_hp;
+}
+
+}  // namespace ksys::act
+
 namespace uking::aoc {
 
 namespace {
diff --git a/src/KingSystem/ActorSystem/actLifeRecoveryInfo.h b/src/KingSystem/ActorSystem/actLifeRecoveryInfo.h
index f382d1b9f..a49924cdf 100644
--- a/src/KingSystem/ActorSystem/actLifeRecoveryInfo.h
+++ b/src/KingSystem/ActorSystem/actLifeRecoveryInfo.h
@@ -23,8 +23,8 @@ class LifeRecoverInfo {
     f32 mCounter;
     f32 mField_4;
     u8 gap_8[16];  // Is this really a gap?
-    u32 mExtraHp1;
-    u32 mExtraHp2;
+    s32 mExtraHp1;
+    s32 mExtraHp2;
     u32 mMaxLife;
     f32 mRecoverFactor;
     s32 mField_28;