diff --git a/git-filter-repo b/git-filter-repo
index aaa4609..a0ad4f7 100755
--- a/git-filter-repo
+++ b/git-filter-repo
@@ -2779,6 +2779,11 @@ class RepoFilter(object):
           abort(_('%s does not match %s') % (decode(refname),
                                              decode(origin_ref)))
 
+      # Make sure there is only one worktree
+      output = subprocess.check_output('git worktree list'.split())
+      if len(output.splitlines()) > 1:
+        abort(_('you have multiple worktrees'))
+
   @staticmethod
   def tweak_blob(args, blob):
     if args.replace_text:
diff --git a/t/t9390-filter-repo.sh b/t/t9390-filter-repo.sh
index 8a674ab..3fd3f5e 100755
--- a/t/t9390-filter-repo.sh
+++ b/t/t9390-filter-repo.sh
@@ -703,6 +703,12 @@ test_expect_success 'startup sanity checks' '
 		test_i18ngrep "you have untracked changes" err &&
 		rm err &&
 
+		git worktree add ../other-worktree HEAD &&
+		test_must_fail git filter-repo --path numbers 2>../err &&
+		test_i18ngrep "you have multiple worktrees" ../err &&
+		rm -rf ../err &&
+		git worktree remove ../other-worktree &&
+
 		git update-ref -d refs/remotes/origin/master &&
 		test_must_fail git filter-repo --path numbers 2>../err &&
 		test_i18ngrep "refs/heads/master exists, but refs/remotes/origin/master not found" ../err &&