diff --git a/share/functions/__fish_seen_subcommand_from.fish b/share/functions/__fish_seen_subcommand_from.fish
index 117607a85..fe9203cdf 100644
--- a/share/functions/__fish_seen_subcommand_from.fish
+++ b/share/functions/__fish_seen_subcommand_from.fish
@@ -5,6 +5,6 @@
 #
 
 function __fish_seen_subcommand_from
-    set regex (string escape --style=regex -- (commandline -pxc)[2..] | string join '|')
+    set -l regex (string escape --style=regex -- (commandline -pxc)[2..] | string join '|')
     string match -rq -- '^'$regex'$' $argv
 end