diff --git a/asm/include/main_02001A30.inc b/asm/include/main_02001A30.inc
deleted file mode 100644
index 3f59c932..00000000
--- a/asm/include/main_02001A30.inc
+++ /dev/null
@@ -1,2 +0,0 @@
-#pragma once
-
diff --git a/asm/main_02001A30.s b/asm/main_02001A30.s
deleted file mode 100644
index f2d576cd..00000000
--- a/asm/main_02001A30.s
+++ /dev/null
@@ -1,18 +0,0 @@
-	.include "asm/macros.inc"
-	.include "main_02001A30.inc"
-
-	.text
-
-; https://decomp.me/scratch/bOtSO
-	arm_func_start UFixedPoint64CmpLt
-UFixedPoint64CmpLt: ; 0x02001A30
-	cmp r0, r2
-	movlo r0, #1
-	bxlo lr
-	movhi r0, #0
-	bxhi lr
-	cmp r1, r3
-	movlo r0, #1
-	movhs r0, #0
-	bx lr
-	arm_func_end UFixedPoint64CmpLt
diff --git a/include/main_020018D0.h b/include/main_020018D0.h
index 253ac59a..7cf5cb6f 100644
--- a/include/main_020018D0.h
+++ b/include/main_020018D0.h
@@ -3,5 +3,6 @@
 
 s32 SinAbs4096(s32 x);
 s32 CosAbs4096(s32 x);
+BOOL UFixedPoint64CmpLt(u32 a_hi, u32 a_lo, u32 b_hi, u32 b_lo);
 
 #endif //PMDSKY_MAIN_020018D0_H
diff --git a/main.lsf b/main.lsf
index 6de52d4a..c9019054 100644
--- a/main.lsf
+++ b/main.lsf
@@ -17,7 +17,6 @@ Static main
 	Object src/main_02001894.o
 	Object asm/main_020018A4.o
 	Object src/main_020018D0.o
-	Object asm/main_02001A30.o
 	Object src/main_02001A54.o
 	Object asm/main_02001B0C.o
 	Object src/main_02001BB4.o
diff --git a/src/main_020018D0.c b/src/main_020018D0.c
index 8b37bc75..8f90c44c 100644
--- a/src/main_020018D0.c
+++ b/src/main_020018D0.c
@@ -36,3 +36,14 @@ s32 CosAbs4096(s32 x)
             return 0;
     }
 }
+
+BOOL UFixedPoint64CmpLt(u32 a_hi, u32 a_lo, u32 b_hi, u32 b_lo)
+{
+    if (a_hi < b_hi) {
+        return TRUE;
+    }
+    if (a_hi > b_hi) {
+        return FALSE;
+    }
+    return a_lo < b_lo;
+}
diff --git a/src/main_02001BB4.c b/src/main_02001BB4.c
index 8032a27b..f5d3a288 100644
--- a/src/main_02001BB4.c
+++ b/src/main_02001BB4.c
@@ -1,7 +1,6 @@
+#include "main_020018D0.h"
 #include "main_02001BB4.h"
 
-extern s32 UFixedPoint64CmpLt(s32, u32, s32, u32);
-
 u32 sub_02001BB4(s32 x, s32 y)
 {
     u32 var_r4;