diff --git a/src/patches.rs b/src/patches.rs
index 8e793e8b..d9ddb3c7 100644
--- a/src/patches.rs
+++ b/src/patches.rs
@@ -11509,53 +11509,76 @@ fn patch_dol(
     dol_patcher.ppcasm_patch(&custom_item_get_item_amount_hook)?;
     let custom_item_get_item_amount_patch = ppcasm!(new_text_section_end, {
             // backup arguments
-            mr           r21, r3;
+            mr           r0, r3;
+            lis          r3, r3_backup@h;
+            addi         r3, r3, r3_backup@l;
+            stw          r0, 0x0(r3);
+            mr           r0, r4;
+            lis          r4, r4_backup@h;
+            addi         r4, r4, r4_backup@l;
+            stw          r0, 0x0(r4);
 
             // preload unknown item 2 for future checks in the function
-            li           r22, { PickupType::UnknownItem2.kind() };
-            rlwinm       r0, r22, 0x3, 0x0, 0x1c;
-            add          r22, r3, r0;
-            addi         r22, r22, 0x2c;
-            lwz          r22, 0x0(r22);
+            lis          r4, r3_backup@h;
+            addi         r4, r4, r3_backup@l;
+            lwz          r4, 0x0(r4);
+            li           r3, { PickupType::UnknownItem2.kind() };
+            rlwinm       r3, r3, 0x3, 0x0, 0x1c;
+            add          r3, r4, r3;
+            addi         r3, r3, 0x2c;
+            lwz          r3, 0x0(r3);
+            mr           r0, r3;
 
+            lis          r4, r4_backup@h;
+            addi         r4, r4, r4_backup@l;
+            lwz          r4, 0x0(r4);
             cmpwi        r4, { PickupType::Missile.kind() };
             bne          check_power_bomb;
             // check for missile launcher
-            andi         r22, r3, { PickupType::MissileLauncher.custom_item_value() };
+            andi         r0, r3, { PickupType::MissileLauncher.custom_item_value() };
             cmpwi        r3, 0;
             beq          no_launcher;
             // check for missile capacity
+            lis          r4, r3_backup@h;
+            addi         r4, r4, r3_backup@l;
+            lwz          r4, 0x0(r4);
             li           r3, { PickupType::Missile.kind() };
-            rlwinm       r0, r3, 0x3, 0x0, 0x1c;
-            add          r3, r21, r0;
+            rlwinm       r3, r3, 0x3, 0x0, 0x1c;
+            add          r3, r4, r3;
             addi         r3, r3, 0x2c;
             lwz          r3, 0x0(r3);
             cmpwi        r3, 0;
             ble          no_launcher;
             // check for unlimited missiles
-            andi         r22, r3, { PickupType::UnlimitedMissiles.custom_item_value() };
+            andi         r0, r3, { PickupType::UnlimitedMissiles.custom_item_value() };
             cmpwi        r3, 0;
             beq          not_unlimited_or_not_pb_missiles;
             li           r3, 255;
             b            is_unlimited;
 
         check_power_bomb:
+            lis          r4, r4_backup@h;
+            addi         r4, r4, r4_backup@l;
+            lwz          r4, 0x0(r4);
             cmpwi        r4, { PickupType::PowerBomb.kind() };
             bne          not_unlimited_or_not_pb_missiles;
             // check for power bomb launcher
-            andi         r22, r3, { PickupType::PowerBombLauncher.custom_item_value() };
+            andi         r0, r3, { PickupType::PowerBombLauncher.custom_item_value() };
             cmpwi        r3, 0;
             beq          no_launcher;
             // check for power bomb capacity
+            lis          r4, r3_backup@h;
+            addi         r4, r4, r3_backup@l;
+            lwz          r4, 0x0(r4);
             li           r3, { PickupType::PowerBomb.kind() };
-            rlwinm       r0, r3, 0x3, 0x0, 0x1c;
-            add          r3, r21, r0;
+            rlwinm       r3, r3, 0x3, 0x0, 0x1c;
+            add          r3, r4, r3;
             addi         r3, r3, 0x2c;
             lwz          r3, 0x0(r3);
             cmpwi        r3, 0;
             ble          no_launcher;
             // check for unlimited power bombs
-            andi         r22, r3, { PickupType::UnlimitedPowerBombs.custom_item_value() };
+            andi         r0, r3, { PickupType::UnlimitedPowerBombs.custom_item_value() };
             cmpwi        r3, 0;
             beq          not_unlimited_or_not_pb_missiles;
             li           r3, 8;
@@ -11564,17 +11587,33 @@ fn patch_dol(
         no_launcher:
             li           r3, 0;
         is_unlimited:
-            andi         r21, r21, 0;
-            andi         r22, r22, 0;
+            lis          r3, r3_backup@h;
+            addi         r3, r3, r3_backup@l;
+            lwz          r3, 0x0(r3);
+            lis          r4, r4_backup@h;
+            addi         r4, r4, r4_backup@l;
+            lwz          r4, 0x0(r4);
             blr;
 
         not_unlimited_or_not_pb_missiles:
             // restore previous context
-            mr           r3, r21;
-            andi         r21, r21, 0;
-            andi         r22, r22, 0;
+            lis          r3, r3_backup@h;
+            addi         r3, r3, r3_backup@l;
+            lwz          r3, 0x0(r3);
+            lis          r4, r4_backup@h;
+            addi         r4, r4, r4_backup@l;
+            lwz          r4, 0x0(r4);
             cmpwi        r4, 0;
-            b            { symbol_addr!("GetItemAmount__12CPlayerStateCFQ212CPlayerState9EItemType", version) + 0x4 };
+            blt          item_type_negative;
+            b            { symbol_addr!("GetItemAmount__12CPlayerStateCFQ212CPlayerState9EItemType", version) + 0x8 };
+        item_type_negative:
+            li           r3, 0;
+            blr;
+
+        r3_backup:
+            .long 0;
+        r4_backup:
+            .long 0;
         });
 
     new_text_section_end += custom_item_get_item_amount_patch.encoded_bytes().len() as u32;