diff --git a/src/prelaunch/h.e.r.o.a b/src/prelaunch/h.e.r.o.a
index 43aa1fab1..4fab9acdf 100644
--- a/src/prelaunch/h.e.r.o.a
+++ b/src/prelaunch/h.e.r.o.a
@@ -1,5 +1,5 @@
 ;license:MIT
-;(c) 2019 by 4am/Frank M.
+;(c) 2019, 2024 by 4am/Frank M., qkumba
 
 !cpu 6502
 !to "build/PRELAUNCH.INDEXED/H.E.R.O",plain
@@ -11,6 +11,24 @@
          lda   #$60
          sta   $4028
          jsr   $4000      ; decompress
+
+         ldx   $FBB3
+         cpx   #6
+         bne   +          ; not a //e or //c
+         ldx   $FBC0
+         bne   +          ; not a //c
+         lda   $C405
+         cmp   #$38
+         bne   not_mouse
+         lda   $C407
+         cmp   #$18
+         beq   +          ; looks like the mouse
+
+not_mouse
+         lda   #0
+         sta   $6032      ; disable mouse-based VBL
+
++
          +GET_MACHINE_STATUS
          and   #CHEATS_ENABLED
          beq   +