diff --git a/share/functions/__fish_complete_group_ids.fish b/share/functions/__fish_complete_group_ids.fish
index 28ea7014b..3e1604219 100644
--- a/share/functions/__fish_complete_group_ids.fish
+++ b/share/functions/__fish_complete_group_ids.fish
@@ -1,7 +1,7 @@
 function __fish_complete_group_ids --description "Complete group IDs with group name as description"
     if command -sq getent
-        getent group | string replace -f -r '^([[:alpha:]][^:]*):[^:]*:(\d+).*' '$2\t$1'
+        getent group | string replace -f -r '^([[:alpha:]_][^:]*):[^:]*:(\d+).*' '$2\t$1'
     else if test -r /etc/group
-        string replace -f -r '^([[:alpha:]][^:]*):[^:]*:(\d+).*' '$2\t$1' </etc/group
+        string replace -f -r '^([[:alpha:]_][^:]*):[^:]*:(\d+).*' '$2\t$1' </etc/group
     end
 end
diff --git a/share/functions/__fish_complete_user_ids.fish b/share/functions/__fish_complete_user_ids.fish
index 2f5e3b675..a48c1f740 100644
--- a/share/functions/__fish_complete_user_ids.fish
+++ b/share/functions/__fish_complete_user_ids.fish
@@ -1,7 +1,7 @@
 function __fish_complete_user_ids --description "Complete user IDs with user name as description"
     if command -sq getent
-        getent passwd | string replace -f -r '^([[:alpha:]][^:]*):[^:]*:(\d+).*' '$2\t$1'
+        getent passwd | string replace -f -r '^([[:alpha:]_][^:]*):[^:]*:(\d+).*' '$2\t$1'
     else if test -r /etc/passwd
-        string replace -f -r '^([[:alpha:]][^:]*):[^:]*:(\d+).*' '$2\t$1' </etc/passwd
+        string replace -f -r '^([[:alpha:]_][^:]*):[^:]*:(\d+).*' '$2\t$1' </etc/passwd
     end
 end