diff --git a/src/include/lib/mtx.h b/src/include/lib/mtx.h
index ac7dc2653..9853414e0 100644
--- a/src/include/lib/mtx.h
+++ b/src/include/lib/mtx.h
@@ -54,7 +54,7 @@ void mtx00016d58(Mtxf *matrix, f32 posx, f32 posy, f32 posz, f32 lookx, f32 look
 u32 mtx00016dcc(f32 arg0, f32 arg1);
 u32 mtx00016e98(void);
 void mtx00017028(f32 mtx[4][4], f32 radians, f32 x, f32 y, f32 z);
-u32 mtx00017070(void);
+void mtx00017070(f32 src[4][4], f32 dst[4][4]);
 u32 mtx000170e4(void);
 u32 mtx0001719c(void);
 u32 mtx000172f0(void);
diff --git a/src/lib/mtx.c b/src/lib/mtx.c
index 981d899ec..7f7ef4cbb 100644
--- a/src/lib/mtx.c
+++ b/src/lib/mtx.c
@@ -892,38 +892,29 @@ glabel func00018000nb
 );
 #endif
 
-GLOBAL_ASM(
-glabel mtx00017070
-/*    17070:	c4840000 */ 	lwc1	$f4,0x0($a0)
-/*    17074:	44800000 */ 	mtc1	$zero,$f0
-/*    17078:	3c013f80 */ 	lui	$at,0x3f80
-/*    1707c:	e4a40000 */ 	swc1	$f4,0x0($a1)
-/*    17080:	c4860010 */ 	lwc1	$f6,0x10($a0)
-/*    17084:	e4a60004 */ 	swc1	$f6,0x4($a1)
-/*    17088:	c4880020 */ 	lwc1	$f8,0x20($a0)
-/*    1708c:	e4a80008 */ 	swc1	$f8,0x8($a1)
-/*    17090:	c48a0004 */ 	lwc1	$f10,0x4($a0)
-/*    17094:	e4aa0010 */ 	swc1	$f10,0x10($a1)
-/*    17098:	c4900014 */ 	lwc1	$f16,0x14($a0)
-/*    1709c:	44815000 */ 	mtc1	$at,$f10
-/*    170a0:	e4b00014 */ 	swc1	$f16,0x14($a1)
-/*    170a4:	c4920024 */ 	lwc1	$f18,0x24($a0)
-/*    170a8:	e4b20018 */ 	swc1	$f18,0x18($a1)
-/*    170ac:	c4840008 */ 	lwc1	$f4,0x8($a0)
-/*    170b0:	e4a40020 */ 	swc1	$f4,0x20($a1)
-/*    170b4:	c4860018 */ 	lwc1	$f6,0x18($a0)
-/*    170b8:	e4a60024 */ 	swc1	$f6,0x24($a1)
-/*    170bc:	c4880028 */ 	lwc1	$f8,0x28($a0)
-/*    170c0:	e4a00030 */ 	swc1	$f0,0x30($a1)
-/*    170c4:	e4a00034 */ 	swc1	$f0,0x34($a1)
-/*    170c8:	e4a00038 */ 	swc1	$f0,0x38($a1)
-/*    170cc:	e4a0000c */ 	swc1	$f0,0xc($a1)
-/*    170d0:	e4a0001c */ 	swc1	$f0,0x1c($a1)
-/*    170d4:	e4a0002c */ 	swc1	$f0,0x2c($a1)
-/*    170d8:	e4aa003c */ 	swc1	$f10,0x3c($a1)
-/*    170dc:	03e00008 */ 	jr	$ra
-/*    170e0:	e4a80028 */ 	swc1	$f8,0x28($a1)
-);
+void mtx00017070(f32 src[4][4], f32 dst[4][4])
+{
+	dst[0][0] = src[0][0];
+	dst[0][1] = src[1][0];
+	dst[0][2] = src[2][0];
+
+	dst[1][0] = src[0][1];
+	dst[1][1] = src[1][1];
+	dst[1][2] = src[2][1];
+
+	dst[2][0] = src[0][2];
+	dst[2][1] = src[1][2];
+	dst[2][2] = src[2][2];
+
+	dst[3][0] = 0;
+	dst[3][1] = 0;
+	dst[3][2] = 0;
+
+	dst[0][3] = 0;
+	dst[1][3] = 0;
+	dst[2][3] = 0;
+	dst[3][3] = 1;
+}
 
 GLOBAL_ASM(
 glabel mtx000170e4