diff --git a/asm/kinstone.s b/asm/kinstone.s
index 1f666fd2..feb23266 100644
--- a/asm/kinstone.s
+++ b/asm/kinstone.s
@@ -220,29 +220,3 @@ _0801868C:
 	pop {r4, r5, pc}
 	.align 2, 0
 
-	thumb_func_start sub_08018690
-sub_08018690: @ 0x08018690
-	push {r4, r5, r6, lr}
-	adds r6, r1, #0
-	subs r4, r0, #1
-	cmp r4, #0
-	beq _080186BC
-	lsls r0, r4, #1
-	adds r5, r0, r6
-_0801869E:
-	bl Random
-	adds r1, r4, #1
-	bl __modsi3
-	ldrh r2, [r5]
-	lsls r0, r0, #1
-	adds r0, r0, r6
-	ldrh r1, [r0]
-	strh r1, [r5]
-	strh r2, [r0]
-	subs r5, #2
-	subs r4, #1
-	cmp r4, #0
-	bne _0801869E
-_080186BC:
-	pop {r4, r5, r6, pc}
-	.align 2, 0
diff --git a/src/kinstone.c b/src/kinstone.c
index 0d4ee14e..c11ac3e2 100644
--- a/src/kinstone.c
+++ b/src/kinstone.c
@@ -7,6 +7,7 @@
 #include "kinstone.h"
 #include "area.h"
 #include "manager.h"
+#include "asm.h"
 
 extern EntityData gUnk_080FEC28[];
 extern EntityData gUnk_080FEBE8[];
@@ -28,6 +29,30 @@ void sub_080189EC(int);
 void sub_0801876C(int, int);
 void sub_08018738(u32, int);
 
+void sub_08018690(int param_1, u16* param_2) {
+    u32 uVar1;
+    s32 uVar4;
+    s32 uVar2;
+    s32 iVar3;
+    u16* puVar4;
+    u16* puVar5;
+
+    uVar4 = param_1 - 1;
+    if (uVar4 != 0) {
+        puVar5 = (u16*)(uVar4 * 2 + (int)param_2);
+        do {
+            uVar2 = Random();
+            iVar3 = uVar2 % (uVar4 + 1);
+            uVar1 = *puVar5;
+            puVar4 = (u16*)(iVar3 * 2 + (int)param_2);
+            *puVar5 = *puVar4;
+            *puVar4 = uVar1;
+            puVar5--;
+            uVar4--;
+        } while (uVar4 != 0);
+    }
+}
+
 void sub_080186C0(u32 param_1) {
     gArea.inventoryGfxIdx = 0xff;
     gArea.unk2C = param_1;