diff --git a/CHANGELOG.md b/CHANGELOG.md
index 73f7dbb..6de1c45 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## Unreleased - 2025-??-??
+- Changed: Metroid Fusion Stereo default IPS patch has been ported into ASM. Instead a flag in ROM will set the default speaker setup to stereo.
+
 ## 0.7.0 - 2025-08-25
 - Added: Ability to write text to the title screen.
 - Removed: Anti-Softlock option.
diff --git a/src/mars_patcher/mf/constants/reserved_space.py b/src/mars_patcher/mf/constants/reserved_space.py
index d1f7aa9..fdc0007 100644
--- a/src/mars_patcher/mf/constants/reserved_space.py
+++ b/src/mars_patcher/mf/constants/reserved_space.py
@@ -22,9 +22,10 @@ class ReservedConstantsMF:
     STARTING_LOCATION_ADDR = 0x7FF014
     CREDITS_END_DELAY_ADDR = 0x7FF018  # TODO: Is this meant to be changed?
     CREDITS_SCROLL_SPEED_ADDR = 0x7FF018  # + 2 TODO: Ditto
-    HINT_SECURITY_LEVELS_ADDR = 0x7FF01C  # TODO: ???
+    HINT_SECURITY_LEVELS_ADDR = 0x7FF01C
     ENVIRONMENTAL_HARZARD_DAMAGE_ADDR = 0x7FF020  # TODO: Implement this
     MISSILE_LIMIT_ADDR = 0x7FF024
     ROOM_NAMES_TABLE_ADDR = 0x7FF028
     REVEAL_HIDDEN_TILES_ADDR = 0x7FF02C
     TITLESCREEN_TEXT_POINTERS_POINTER_ADDR = 0x7FF030
+    DEFAULT_STEREO_FLAG_POINTER_ADDR = 0x7FF034
diff --git a/src/mars_patcher/mf/data/patches/mf_u/free_space.txt b/src/mars_patcher/mf/data/patches/mf_u/free_space.txt
deleted file mode 100644
index b85845b..0000000
--- a/src/mars_patcher/mf/data/patches/mf_u/free_space.txt
+++ /dev/null
@@ -1,3 +0,0 @@
-Address     Name
-80F9A28     stereo_default
-80F9A4C
diff --git a/src/mars_patcher/mf/data/patches/mf_u/stereo_default.ips b/src/mars_patcher/mf/data/patches/mf_u/stereo_default.ips
deleted file mode 100644
index a41a7dd..0000000
Binary files a/src/mars_patcher/mf/data/patches/mf_u/stereo_default.ips and /dev/null differ
diff --git a/src/mars_patcher/mf/misc_patches.py b/src/mars_patcher/mf/misc_patches.py
index d50aa6f..9ea6513 100644
--- a/src/mars_patcher/mf/misc_patches.py
+++ b/src/mars_patcher/mf/misc_patches.py
@@ -43,7 +43,7 @@ def skip_door_transitions(rom: Rom) -> None:
 
 
 def stereo_default(rom: Rom) -> None:
-    apply_patch_in_data_path(rom, "stereo_default.ips")
+    rom.write_8(rom.read_ptr(ReservedConstantsMF.DEFAULT_STEREO_FLAG_POINTER_ADDR), 1)
 
 
 def disable_sounds(rom: Rom, start: int, end: int, exclude: set[int] = set()) -> None: