diff --git a/sdata/subcmd-virtmon/0.run.sh b/sdata/subcmd-virtmon/0.run.sh
index ea22c1643..f66312204 100644
--- a/sdata/subcmd-virtmon/0.run.sh
+++ b/sdata/subcmd-virtmon/0.run.sh
@@ -22,11 +22,32 @@ echo "Creating headless monitor..."
 readarray -t vmons_old < <(hyprctl -j monitors all | jq -r '.[] | select(.name | test("^HEADLESS-")) | .name')
 x hyprctl output create headless
 readarray -t vmons_new < <(hyprctl -j monitors all | jq -r '.[] | select(.name | test("^HEADLESS-")) | .name')
+declare -A seen
+for e in "${vmons_old[@]}"; do
+  seen["$e"]=1
+done
+deltas=()
+for e in "${vmons_new[@]}"; do
+  if [[ -z "${seen[$e]+_}" ]]; then
+    deltas+=("$e")
+  fi
+done
+if (( ${#deltas[@]} == 1 )); then
+  vmon_tester="${deltas[0]}"
+  echo "New virtual monitor found: $vmons_tester"
+elif (( ${#deltas[@]} == 0 )); then
+  echo "Error: No new virtual monitor found"
+  exit 1
+else
+  echo "Error: multiple new virtual monitor found: ${deltas[*]}"
+  exit 1
+fi
 #echo "Setting geometry..."
 #${vmon_new}
 
 echo "Using wayvnc to share monitor..."
-wayvnc -o=${vmon_new} --log-level=trace 0.0.0.0 5901
+# TODO: handle port properly
+wayvnc -o=${vmon_tester} --log-level=trace 0.0.0.0 5901
 
 echo "Cleaning the new headless monitor..."
-x hyprctl output remove "${vmon_new}"
+x hyprctl output remove "${vmon_tester}"