diff --git a/share/completions/optipng.fish b/share/completions/optipng.fish
index 027fdecf0..03ef9b639 100644
--- a/share/completions/optipng.fish
+++ b/share/completions/optipng.fish
@@ -37,6 +37,6 @@ complete -x -c optipng -n '__fish_should_complete_switches' -a '-dir\t"write out
 complete -x -c optipng -n '__fish_should_complete_switches' -a '-log\t"log messages to <file>"'
 
 complete -x -c optipng -n 'not __fish_prev_arg_in -out -dir -log' \
-    -a '(__fish_complete_suffix .png;  __fish_complete_suffix .pnm;  __fish_complete_suffix .tiff;  __fish_complete_suffix .bmp)
+    -a '(__fish_complete_suffix .png;  __fish_complete_suffix .pnm;  __fish_complete_suffix .tiff;  __fish_complete_suffix .bmp)'
 
 complete -x -c optipng -n '__fish_prev_arg_in -dir' -a '(__fish_complete_directories)'