diff --git a/libsrc/mouse/mouse-kernel.s b/libsrc/mouse/mouse-kernel.s
index 624088078..3cb9a2fa5 100644
--- a/libsrc/mouse/mouse-kernel.s
+++ b/libsrc/mouse/mouse-kernel.s
@@ -85,6 +85,7 @@ _mouse_install:
         sty     tmp1
 
 @L2:    jsr     copycb
+        ldy     tmp1
         jsr     copycb
         dec     tmp2                    ; Skip opcode byte
         ldy     tmp1