diff --git a/source/reg-ios-64.spin b/source/reg-ios-64.spin
index eb8c309..f28ef7f 100644
--- a/source/reg-ios-64.spin
+++ b/source/reg-ios-64.spin
@@ -1462,7 +1462,7 @@ PUB sid_dmpstatus: status
 PUB sid_dmppos: wert
   bus_putchar1(gc#a_s_dmppos)
   wert := bus_getlong1
-          bus_getlong1
+  wert := bus_getlong1 - wert
 
 PUB sid_dmplen: wert
   bus_putchar1(gc#a_s_dmppos)