diff --git a/git-am.sh b/git-am.sh
index a67d0f9898..1f4c09e3d4 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -297,6 +297,7 @@ split_patches () {
 		;;
 	stgit)
 		this=0
+		test 0 -eq "$#" && set -- -
 		for stgit in "$@"
 		do
 			this=$(expr "$this" + 1)
@@ -318,7 +319,7 @@ split_patches () {
 					print "Subject: ", $_ ;
 					$subject = 1;
 				}
-			' < "$stgit" > "$dotest/$msgnum" || clean_abort
+			' -- "$stgit" >"$dotest/$msgnum" || clean_abort
 		done
 		echo "$this" > "$dotest/last"
 		this=
diff --git a/t/t4150-am.sh b/t/t4150-am.sh
index 0ead529a2f..51962e481e 100755
--- a/t/t4150-am.sh
+++ b/t/t4150-am.sh
@@ -209,6 +209,16 @@ test_expect_success 'am applies stgit patch' '
 	test_cmp_rev second^ HEAD^
 '
 
+test_expect_success 'am --patch-format=stgit applies stgit patch' '
+	rm -fr .git/rebase-apply &&
+	git checkout -f first &&
+	git am --patch-format=stgit <patch1-stgit.eml &&
+	test_path_is_missing .git/rebase-apply &&
+	git diff --exit-code second &&
+	test_cmp_rev second HEAD &&
+	test_cmp_rev second^ HEAD^
+'
+
 test_expect_success 'setup: new author and committer' '
 	GIT_AUTHOR_NAME="Another Thor" &&
 	GIT_AUTHOR_EMAIL="a.thor@example.com" &&