diff --git a/libsrc/lynx/ser/lynx-comlynx.s b/libsrc/lynx/ser/lynx-comlynx.s
index 7201264b7..9b007c6e0 100644
--- a/libsrc/lynx/ser/lynx-comlynx.s
+++ b/libsrc/lynx/ser/lynx-comlynx.s
@@ -74,7 +74,7 @@ SER_UNINSTALL:
 
 SER_CLOSE:
         ; Disable interrupts and stop timer 4 (serial)
-        lda     #$0C  ; TXOPEN|RESETERR
+        lda     #TXOPEN|RESETERR
         sta     SERCTL
         lda     #$00  ; Disable count and no reload
         sta     TIM4CTLA