diff --git a/dump/dump.c b/dump/dump.c
index 73a231a..7e30f34 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -247,8 +247,7 @@ int main(int argc, char *argv[])
 	if (argc < 2)
 		usage();
 
-	memset(ui.dev_name, 0, sizeof(ui.dev_name));
-	snprintf(ui.dev_name, sizeof(ui.dev_name), "%s", argv[1]);
+	ui.dev_name = argv[1];
 
 	ret = exfat_get_blk_dev_info(&ui, &bd);
 	if (ret < 0)
diff --git a/exfat2img/exfat2img.c b/exfat2img/exfat2img.c
index bd9db44..e75b42f 100644
--- a/exfat2img/exfat2img.c
+++ b/exfat2img/exfat2img.c
@@ -926,7 +926,7 @@ int main(int argc, char * const argv[])
 	}
 
 	memset(&ui, 0, sizeof(ui));
-	snprintf(ui.dev_name, sizeof(ui.dev_name), "%s", blkdev_path);
+	ui.dev_name = blkdev_path;
 	if (restore)
 		ui.writeable = true;
 	else
diff --git a/fsck/fsck.c b/fsck/fsck.c
index fe8a122..7cac445 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -1616,7 +1616,7 @@ int main(int argc, char * const argv[])
 
 	exfat_fsck.options = ui.options;
 
-	snprintf(ui.ei.dev_name, sizeof(ui.ei.dev_name), "%s", argv[optind]);
+	ui.ei.dev_name = argv[optind];
 	ret = exfat_get_blk_dev_info(&ui.ei, &bd);
 	if (ret < 0) {
 		exfat_err("failed to open %s. %d\n", ui.ei.dev_name, ret);
diff --git a/include/libexfat.h b/include/libexfat.h
index 2ed9aa7..06b5498 100644
--- a/include/libexfat.h
+++ b/include/libexfat.h
@@ -78,7 +78,7 @@ struct exfat_blk_dev {
 };
 
 struct exfat_user_input {
-	char dev_name[255];
+	const char *dev_name;
 	bool writeable;
 	unsigned int sector_size;
 	unsigned int cluster_size;
diff --git a/label/label.c b/label/label.c
index 2780143..c5eea7a 100644
--- a/label/label.c
+++ b/label/label.c
@@ -81,8 +81,7 @@ int main(int argc, char *argv[])
 	if (argc < 2)
 		usage();
 
-	memset(ui.dev_name, 0, sizeof(ui.dev_name));
-	snprintf(ui.dev_name, sizeof(ui.dev_name), "%s", argv[serial_mode + 1]);
+	ui.dev_name = argv[serial_mode + 1];
 
 	ret = exfat_get_blk_dev_info(&ui, &bd);
 	if (ret < 0)
diff --git a/mkfs/mkfs.c b/mkfs/mkfs.c
index f9286c1..71f2b10 100644
--- a/mkfs/mkfs.c
+++ b/mkfs/mkfs.c
@@ -737,8 +737,7 @@ int main(int argc, char *argv[])
 		goto out;
 	}
 
-	memset(ui.dev_name, 0, sizeof(ui.dev_name));
-	snprintf(ui.dev_name, sizeof(ui.dev_name), "%s", argv[optind]);
+	ui.dev_name = argv[optind];
 
 	ret = exfat_get_blk_dev_info(&ui, &bd);
 	if (ret < 0)
diff --git a/tune/tune.c b/tune/tune.c
index 4966e0a..218e840 100644
--- a/tune/tune.c
+++ b/tune/tune.c
@@ -118,8 +118,7 @@ int main(int argc, char *argv[])
 	if (argc < 3)
 		usage();
 
-	memset(ui.dev_name, 0, sizeof(ui.dev_name));
-	snprintf(ui.dev_name, sizeof(ui.dev_name), "%s", argv[argc - 1]);
+	ui.dev_name = argv[argc - 1];
 
 	ret = exfat_get_blk_dev_info(&ui, &bd);
 	if (ret < 0)