diff --git a/README.md b/README.md
index 49971d5..cd75823 100644
--- a/README.md
+++ b/README.md
@@ -208,7 +208,6 @@ topgrade
 
 ## TODO
 
-* add zsh completion
 * add license
 * in outermost Cargo.toml, add categories, keywords, readme
 
diff --git a/_completion.zsh b/_completion.zsh
new file mode 100644
index 0000000..6b547b2
--- /dev/null
+++ b/_completion.zsh
@@ -0,0 +1,64 @@
+#compdef pacdef
+
+_pacdef() {
+    integer ret=1
+    local line
+    function _actions {
+        local -a actions
+        actions=(
+            'clean:uninstall packages not managed by pacdef'
+            'edit:edit an imported group file'
+            'groups:show names of imported groups'
+            'import:import a new group file'
+            'new:create a new group file'
+            'remove:remove a group file'
+            'review:review unmanaged packages'
+            'search:show the group containing a package'
+            'show:show packages under an imported group'
+            'sync:install all packages from imported groups'
+            'unmanaged:show explicitly installed packages not managed by pacdef'
+            'version:show version info'
+        )
+        _describe 'action' actions
+    }
+
+    _arguments \
+        "1: :_actions" \
+        "*::arg:->args"
+
+    if [ -z "${XDG_CONFIG_HOME}" ]; then
+        GROUPDIR="~/.config/pacdef/groups"
+    else
+        GROUPDIR="${XDG_CONFIG_HOME}/pacdef/groups"
+    fi
+
+
+    case $line[1] in
+        edit)
+            _arguments "1:group file:_files -W '$GROUPDIR'"
+        ;;
+        import)
+            _arguments "*:new group file(s):_files"
+        ;;
+        new)
+            _arguments "*:new group file(s):"
+        ;;
+        search)
+            _arguments "1:package:"
+        ;;
+        show)
+            _arguments "1:group file:_files -W '$GROUPDIR'"
+        ;;
+        remove)
+            _arguments "*:group file:_files -W '$GROUPDIR'"
+        ;;
+        "") ;;
+        *)
+            _message "no more arguments"
+        ;;
+    esac
+
+    return ret
+}
+
+_pacdef