diff --git a/asm/kinstone.s b/asm/kinstone.s
index e99455cb..259ed9db 100644
--- a/asm/kinstone.s
+++ b/asm/kinstone.s
@@ -707,51 +707,3 @@ _08018A48: .4byte gUnk_080FE320
 _08018A4C: .4byte 0x000001DF
 _08018A50: .4byte 0x000001E3
 _08018A54: .4byte 0x000001DB
-
-	thumb_func_start sub_08018A58
-sub_08018A58: @ 0x08018A58
-	push {r4, r5, r6, r7, lr}
-	mov r7, r8
-	push {r7}
-	lsls r1, r0, #2
-	adds r1, r1, r0
-	lsls r1, r1, #2
-	ldr r0, _08018AAC @ =gUnk_080FE320
-	adds r1, r1, r0
-	ldrh r0, [r1, #8]
-	lsrs r5, r0, #4
-	movs r2, #0x3f
-	ands r5, r2
-	ldrh r0, [r1, #0xa]
-	lsrs r0, r0, #4
-	ands r0, r2
-	lsls r0, r0, #6
-	orrs r5, r0
-	subs r5, #0x43
-	ldr r6, _08018AB0 @ =0x00000232
-	movs r0, #0
-_08018A80:
-	movs r4, #0
-	movs r1, #0x40
-	adds r1, r1, r5
-	mov r8, r1
-	adds r7, r0, #1
-_08018A8A:
-	adds r0, r6, #0
-	adds r6, #1
-	adds r1, r5, r4
-	movs r2, #1
-	bl SetTileType
-	adds r4, #1
-	cmp r4, #6
-	bls _08018A8A
-	mov r5, r8
-	adds r0, r7, #0
-	cmp r0, #3
-	bls _08018A80
-	pop {r3}
-	mov r8, r3
-	pop {r4, r5, r6, r7, pc}
-	.align 2, 0
-_08018AAC: .4byte gUnk_080FE320
-_08018AB0: .4byte 0x00000232
diff --git a/src/kinstone.c b/src/kinstone.c
index 5d0cceef..29b35f26 100644
--- a/src/kinstone.c
+++ b/src/kinstone.c
@@ -4,6 +4,27 @@
 #include "common.h"
 #include "flags.h"
 
+void sub_08018A58(int param_1) {
+    u32 i;
+    int iVar2;
+    u32 j;
+    int tilePosition;
+    struct_080FE320* ptr;
+
+    ptr = &gUnk_080FE320[param_1];
+
+    tilePosition = (ptr->x >> 4) & 0x3f;
+    tilePosition |= ((ptr->y >> 4) & 0x3f) << 6;
+    tilePosition -= 0x43;
+    iVar2 = 0x232;
+
+    for (i = 0; i < 4; tilePosition += 0x40, i++) {
+        for (j = 0; j < 7; j++) {
+            SetTileType(iVar2++, tilePosition + j, 1);
+        }
+    }
+}
+
 void sub_08018AB4(int param_1) {
     u32 i;
     int iVar2;