diff --git a/mainmem.shr.s b/mainmem.shr.s
index 74739e5..a363a98 100644
--- a/mainmem.shr.s
+++ b/mainmem.shr.s
@@ -118,7 +118,8 @@ SHRUSERCHAR   >>>   ENTMAIN
               CPY   #$08                   ; Last row?
               BNE   :L1
 :DONE         >>>   XF2AUX,VDU23RET
-:INCREMENT    DB    $00
+* Zero page
+:INCREMENT    EQU   TMPZP+0
 
 
 * Explode one row of pixels. Used by SHRXPLDCHAR & SHRUSERCHAR