diff --git a/builtin/commit.c b/builtin/commit.c
index 9ab57ea1aa..65a5c0e29d 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1043,7 +1043,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		struct child_process run_trailer = CHILD_PROCESS_INIT;
 
 		strvec_pushl(&run_trailer.args, "interpret-trailers",
-			     "--in-place", git_path_commit_editmsg(), NULL);
+			     "--in-place", "--no-divider",
+			     git_path_commit_editmsg(), NULL);
 		strvec_pushv(&run_trailer.args, trailer_args.v);
 		run_trailer.git_cmd = 1;
 		if (run_command(&run_trailer))
diff --git a/t/t7502-commit-porcelain.sh b/t/t7502-commit-porcelain.sh
index 38a532d81c..b5bf7de7cd 100755
--- a/t/t7502-commit-porcelain.sh
+++ b/t/t7502-commit-porcelain.sh
@@ -466,6 +466,25 @@ test_expect_success 'commit --trailer with -c and command' '
 	test_cmp expected actual
 '
 
+test_expect_success 'commit --trailer not confused by --- separator' '
+	cat >msg <<-\EOF &&
+	subject
+
+	body with dashes
+	---
+	in it
+	EOF
+	git commit --allow-empty --trailer="my-trailer: value" -F msg &&
+	{
+		cat msg &&
+		echo &&
+		echo "my-trailer: value"
+	} >expected &&
+	git cat-file commit HEAD >commit.msg &&
+	sed -e "1,/^\$/d" commit.msg >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'multiple -m' '
 
 	>negative &&