diff --git a/drivers/md/dm-queue-length.c b/drivers/md/dm-queue-length.c
index 03a837a..3941fae 100644
--- a/drivers/md/dm-queue-length.c
+++ b/drivers/md/dm-queue-length.c
@@ -112,6 +112,7 @@
 	struct selector *s = ps->context;
 	struct path_info *pi;
 	unsigned repeat_count = QL_MIN_IO;
+	char dummy;
 
 	/*
 	 * Arguments: [<repeat_count>]
@@ -123,7 +124,7 @@
 		return -EINVAL;
 	}
 
-	if ((argc == 1) && (sscanf(argv[0], "%u", &repeat_count) != 1)) {
+	if ((argc == 1) && (sscanf(argv[0], "%u%c", &repeat_count, &dummy) != 1)) {
 		*error = "queue-length ps: invalid repeat count";
 		return -EINVAL;
 	}