diff --git a/firehose.c b/firehose.c
index 974180c..da3ed31 100644
--- a/firehose.c
+++ b/firehose.c
@@ -417,9 +417,9 @@ static int firehose_program(struct qdl_device *qdl, struct program *program, int
 		fprintf(stderr, "[PROGRAM] failed\n");
 	} else if (t) {
 		fprintf(stderr,
-			"[PROGRAM] flashed \"%s\" successfully at %ldkB/s\n",
+			"[PROGRAM] flashed \"%s\" successfully at %lukB/s\n",
 			program->label,
-			program->sector_size * num_sectors / t / 1024);
+			(unsigned long)program->sector_size * num_sectors / t / 1024);
 	} else {
 		fprintf(stderr, "[PROGRAM] flashed \"%s\" successfully\n",
 			program->label);