diff --git a/asm/kinstone.s b/asm/kinstone.s
index ce9a9af8..45621207 100644
--- a/asm/kinstone.s
+++ b/asm/kinstone.s
@@ -97,39 +97,3 @@ _0801858C:
 	.align 2, 0
 _080185B0: .4byte gUnk_080B3D20
 
-	thumb_func_start sub_080185B4
-sub_080185B4: @ 0x080185B4
-	push {lr}
-	adds r2, r0, #0
-	ldrb r0, [r2]
-	cmp r0, #0xff
-	bne _080185C2
-	movs r0, #0
-	b _080185F6
-_080185C2:
-	cmp r0, #0xfe
-	bne _080185D4
-	ldrb r0, [r2, #1]
-	bl GetInventoryValue
-	cmp r0, #0
-	beq _080185F6
-	movs r0, #1
-	b _080185F6
-_080185D4:
-	cmp r0, #0xfd
-	beq _080185F0
-	ldr r1, _080185EC @ =gLocalFlagBanks
-	ldrb r0, [r2]
-	lsls r0, r0, #1
-	adds r0, r0, r1
-	ldrh r0, [r0]
-	ldrb r1, [r2, #1]
-	bl CheckLocalFlagByBank
-	b _080185F6
-	.align 2, 0
-_080185EC: .4byte gLocalFlagBanks
-_080185F0:
-	ldrb r0, [r2, #1]
-	bl CheckKinstoneFused
-_080185F6:
-	pop {pc}
diff --git a/src/kinstone.c b/src/kinstone.c
index 9d54ae81..d4cf1cf3 100644
--- a/src/kinstone.c
+++ b/src/kinstone.c
@@ -38,7 +38,20 @@ void sub_0801876C(int, int);
 void sub_08018738(u32, int);
 void sub_08018690(int param_1, u16* param_2);
 void sub_08018500();
-bool32 sub_080185B4(const struct_gUnk_080B3D20*);
+
+bool32 sub_080185B4(const struct_gUnk_080B3D20* param_1) {
+    if (param_1->unk0 == 0xff)
+        return 0;
+
+    if (param_1->unk0 == 0xfe) {
+        return GetInventoryValue(param_1->unk1) != 0;
+    }
+
+    if (param_1->unk0 == 0xfd) {
+        return CheckKinstoneFused(param_1->unk1);
+    }
+    return CheckLocalFlagByBank(gLocalFlagBanks[param_1->unk0], param_1->unk1);
+}
 
 void sub_080185F8(void) {
     struct_area_28* ptr2 = &gArea.unk28;