diff --git a/lib/sg_split.c b/lib/sg_split.c
index b063410..60a0bab 100644
--- a/lib/sg_split.c
+++ b/lib/sg_split.c
@@ -1,10 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2015 Robert Jarzmik <robert.jarzmik@free.fr>
  *
  * Scatterlist splitting helpers.
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2. See the file COPYING for more details.
  */
 
 #include <linux/scatterlist.h>
@@ -178,11 +176,13 @@
 	 * The order of these 3 calls is important and should be kept.
 	 */
 	sg_split_phys(splitters, nb_splits);
-	ret = sg_calculate_split(in, in_mapped_nents, nb_splits, skip,
-				 split_sizes, splitters, true);
-	if (ret < 0)
-		goto err;
-	sg_split_mapped(splitters, nb_splits);
+	if (in_mapped_nents) {
+		ret = sg_calculate_split(in, in_mapped_nents, nb_splits, skip,
+					 split_sizes, splitters, true);
+		if (ret < 0)
+			goto err;
+		sg_split_mapped(splitters, nb_splits);
+	}
 
 	for (i = 0; i < nb_splits; i++) {
 		out[i] = splitters[i].out_sg;