diff --git a/src/fixed/room.h b/src/fixed/room.h
index 43f98f3..c8c25f3 100644
--- a/src/fixed/room.h
+++ b/src/fixed/room.h
@@ -185,7 +185,7 @@ void Sector::getTriggerFloorCeiling(int32 x, int32 y, int32 z, int32* floor, int
     } while (!FD_END(cmd));
 }
 
-
+#ifndef USE_ASM
 const Sector* Room::getSector(int32 x, int32 z) const
 {
     // TODO remove clamp?
@@ -194,6 +194,7 @@ const Sector* Room::getSector(int32 x, int32 z) const
 
     return sectors + sx * info->zSectors + sz;
 }
+#endif
 
 const Sector* Room::getWaterSector(int32 x, int32 z) const
 {
diff --git a/src/platform/gba/asm/getSector.s b/src/platform/gba/asm/getSector.s
new file mode 100644
index 0000000..49d6147
--- /dev/null
+++ b/src/platform/gba/asm/getSector.s
@@ -0,0 +1,44 @@
+#include "common_asm.inc"
+
+this      .req r0
+x         .req r1
+z         .req r2
+info      .req r3
+roomX     .req r12
+roomZ     .req roomX
+sx        .req x
+sz        .req z
+sectors   .req this
+sectorsX  .req roomX
+sectorsZ  .req roomZ
+offset    .req sectorsZ
+
+// const Sector* Room::getSector(int32 x, int32 z) const
+.global _ZNK4Room9getSectorEii
+_ZNK4Room9getSectorEii:
+    ldr info, [this, #4]
+
+    // sx = X_CLAMP((x - (info->x << 8)) >> 10, 0, info->xSectors - 1);
+    ldrsh roomX, [info]
+    subs sx, x, roomX, lsl #8
+    movlt sx, #0
+    mov sx, sx, lsr #10
+    ldrb sectorsX, [info, #20]
+    cmp sx, sectorsX
+    subge sx, sectorsX, #1
+
+    // sz = X_CLAMP((z - (info->z << 8)) >> 10, 0, info->zSectors - 1);
+    ldrsh roomZ, [info, #2]
+    subs sz, z, roomZ, lsl #8
+    movlt sz, #0
+    mov sz, sz, lsr #10
+    ldrb sectorsZ, [info, #21]
+    cmp sz, sectorsZ
+    subge sz, sectorsZ, #1
+
+    // return sectors + sx * info->zSectors + sz;
+    ldr sectors, [this, #8]
+    mla offset, sx, sectorsZ, sz
+    add sectors, offset, lsl #3 // sizeof(Sector) == (1 << 3)
+
+    bx lr