diff --git a/share/completions/chown.fish b/share/completions/chown.fish
index 11eb6fae7..5d72dfd24 100644
--- a/share/completions/chown.fish
+++ b/share/completions/chown.fish
@@ -9,4 +9,4 @@ complete -c chown -s v -l verbose -d "Output diagnostic for every file"
 complete -c chown -s h -l help -d "Display help and exit"
 complete -c chown -l version -d "Display version and exit"
 complete -c chown -d "Username" -a "(__fish_print_users):"
-complete -c chown -d "Username" -a "(string match -r '.*:' (commandline -ct))(__fish_complete_groups)"
+complete -c chown -d "Username" -a "(string match -r -- '.*:' (commandline -ct))(__fish_complete_groups)"