diff --git a/apps/m9zCtrlTty/firefox_install.go b/apps/m9zCtrlTty/firefox_install.go
index 1cb1b49..9d51d01 100644
--- a/apps/m9zCtrlTty/firefox_install.go
+++ b/apps/m9zCtrlTty/firefox_install.go
@@ -139,11 +139,24 @@ select_deb() {
   cp -v "$deb" /opt/firefox-installable/
   selected_count=$((selected_count + 1))
 }
+package_name_from_deb() {
+  pkg=$(dpkg-deb -f "$1" Package 2>/dev/null || true)
+  if [ -n "$pkg" ]; then
+    echo "$pkg"
+    return 0
+  fi
+  file=$(basename "$1")
+  echo "$file" | cut -d '_' -f 1 | sed 's/[.]deb$//'
+}
 for deb in /opt/firefox-deb/*.deb; do
   [ -e "$deb" ] || continue
   file=$(basename "$deb")
-  pkg=${file%%_*}
-  pkg=${pkg%%.deb}
+  pkg=$(package_name_from_deb "$deb")
+  if [ -z "$pkg" ]; then
+    echo "skip package with empty name: $file"
+    continue
+  fi
+  echo "package candidate: $file package=$pkg"
 
   status=$(dpkg-query -W -f='${Status}' "$pkg" 2>/dev/null || true)
   installed=0