diff --git a/src/Cockpit/hud_dnst.cxx b/src/Cockpit/hud_dnst.cxx
index baa2d7981..9dbb190f4 100644
--- a/src/Cockpit/hud_dnst.cxx
+++ b/src/Cockpit/hud_dnst.cxx
@@ -11,7 +11,7 @@ dual_instr_item::dual_instr_item(
         bool         working,
         UINT         options) :
     instr_item(x, y, width, height,
-                chn1_source, options, working),
+                chn1_source, 1, options, working),
                 alt_data_source(chn2_source)
 {
 }