diff --git a/msu.asm b/msu.asm
index 0333c20..4af1caf 100644
--- a/msu.asm
+++ b/msu.asm
@@ -326,7 +326,7 @@ CheckMusicLoadRequest:
 .sfx_indoors
         LDA !REG_MUSIC_CONTROL_REQUEST : STA !REG_MUSIC_CONTROL : STZ !REG_MUSIC_CONTROL_REQUEST
     PLY : PLX : PLA : PLP
-    LDA.b #$05 : STA $012D
+    PHP : SEP #$20 : LDA.b #$05 : STA $012D : PLP
     JML Module_PreDungeon_setAmbientSfx
 ;--------------------------------------------------------------------------------