diff --git a/share/completions/git.fish b/share/completions/git.fish
index 592d358b2..89057e342 100644
--- a/share/completions/git.fish
+++ b/share/completions/git.fish
@@ -2571,9 +2571,9 @@ function __fish_git_complete_custom_command -a subcommand
     set -e cmd[1] # Drop "git".
     set -l subcommand_args
     if argparse -s (__fish_git_global_optspecs) -- $cmd
-        set subcommand_args $argv[2..] # Drop the subcommand.
+        set subcommand_args (string escape -- $argv[2..]) # Drop the subcommand.
     end
-    complete -C "git-$subcommand $(string escape -- $subcommand_args) "(commandline -ct)
+    complete -C "git-$subcommand $subcommand_args "(commandline -ct)
 end
 
 # source git-* commands' autocompletion file if exists
diff --git a/tests/checks/git.fish b/tests/checks/git.fish
index 5e3d71cf3..4af64cd4f 100644
--- a/tests/checks/git.fish
+++ b/tests/checks/git.fish
@@ -51,6 +51,10 @@ complete -C'git frobnicate --onto '
 #CHECK: onto1
 #CHECK: onto2
 
+complete -C'git frobnicate graft --onto '
+#CHECK: onto1
+#CHECK: onto2
+
 complete -C'git ' | grep '^add'\t
 # (note: actual tab character in the check here)
 #CHECK: add	Add file contents to the staging area