diff --git a/Masks/mask_routines.asm b/Masks/mask_routines.asm
index 2725331..6ab52b5 100644
--- a/Masks/mask_routines.asm
+++ b/Masks/mask_routines.asm
@@ -338,6 +338,10 @@ Link_TransformMask:
 Link_TransformMoosh:
 {
   PHB : PHK : PLB
+  LDA.b $1B : BEQ ++
+    %ErrorBeep()
+    JMP .done
+  ++
   LDA.w !CurrentMask : CMP.b #$07 : BNE +
     %PlayerTransform()
     JSL ResetToLinkGraphics
@@ -347,7 +351,7 @@ Link_TransformMoosh:
   LDA.b #$33 : STA $BC
   %PlayerTransform()
   JSL Palette_ArmorAndGloves
-
+  .done
   PLB
   RTL
 }
diff --git a/Sprites/ZSpriteLib/sprite_macros.asm b/Sprites/ZSpriteLib/sprite_macros.asm
index f0a169a..ccd392d 100644
--- a/Sprites/ZSpriteLib/sprite_macros.asm
+++ b/Sprites/ZSpriteLib/sprite_macros.asm
@@ -218,6 +218,10 @@ macro SetTimerF(length)
   LDA.b #<length> : STA.w SprTimerF, X
 endmacro
 
+macro ErrorBeep()
+  LDA.b #$3C : STA.w $012E ; Error beep
+endmacro
+
 macro NextAction()
   INC $0D80, X
 endmacro