diff --git a/linux/completion/_falkon b/linux/completion/_falkon
--- a/linux/completion/_falkon
+++ b/linux/completion/_falkon
@@ -19,6 +19,7 @@
     '(-)'{-r,--no-remote}'[open new browser instance]'
     '(-)'{-c,--current-tab=}'[open URL in current tab]'
     '(-)'{-u,--open-window=}'[open URL in new window]'
+    '--wmclass[application class (X11 only)]'
     '*:files:_files'
     )
 
diff --git a/linux/completion/falkon b/linux/completion/falkon
--- a/linux/completion/falkon
+++ b/linux/completion/falkon
@@ -11,7 +11,7 @@
           -e --no-extensions -o --portable -t --new-tab
           -w --new-window -i --private-browsing -d --download-manager
           -f --fullscreen -r --no-remote -c --current-tab=
-          -u --open-window="
+          -u --open-window= --wmclass"
 
     if [[ ${cur} == -* ]] ; then
         COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )