diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index ba8b67039d13eac2a81835a92d3241375fb43d3d..01e64270e246bef1070c9e68a3603051b02bf919 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -570,7 +570,7 @@ static ssize_t filter_write(struct file *file, const char __user *userbuf,
 	 * Now parse out the first token and use it as the name for the
 	 * driver to filter for.
 	 */
-	for (i = 0; i < NAME_MAX_LEN; ++i) {
+	for (i = 0; i < NAME_MAX_LEN - 1; ++i) {
 		current_driver_name[i] = buf[i];
 		if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0)
 			break;