diff --git a/reset.c b/reset.c
index 4bde5d8dc6..06f375f296 100644
--- a/reset.c
+++ b/reset.c
@@ -122,7 +122,10 @@ int reset_working_tree(struct repository *r,
 		goto leave_reset_head;
 	}
 
-	if (!repo_get_oid(r, "HEAD", &head_oid)) {
+	if (opts->oid_from) {
+		oidcpy(&head_oid, opts->oid_from);
+		head = &head_oid;
+	} else if (!repo_get_oid(r, "HEAD", &head_oid)) {
 		head = &head_oid;
 	} else if (!oid || !reset_hard) {
 		ret = error(_("could not determine HEAD revision"));
diff --git a/reset.h b/reset.h
index 38b2891b53..4c992ba671 100644
--- a/reset.h
+++ b/reset.h
@@ -37,6 +37,11 @@ struct reset_working_tree_options {
 	 * The commit to checkout/reset to. Defaults to HEAD.
 	 */
 	const struct object_id *oid;
+	/*
+	 * The commit to checkout/reset from when doing a two-way merge. This
+	 * is used as one of the sides to merge.
+	 */
+	const struct object_id *oid_from;
 	/*
 	 * Optional value to set ORIG_HEAD. Defaults to HEAD.
 	 */