diff --git a/linux_mtd.c b/linux_mtd.c
index 23041d4..3725920 100644
--- a/linux_mtd.c
+++ b/linux_mtd.c
@@ -49,7 +49,7 @@
 	int i;
 	size_t bytes_read;
 	FILE *fp;
-	char path[strlen(LINUX_MTD_SYSFS_ROOT) + 32];
+	char path[sizeof(LINUX_MTD_SYSFS_ROOT) + 32];
 
 	snprintf(path, sizeof(path), "%s/%s", sysfs_path, filename);