diff --git a/src/trau_frame.c b/src/trau_frame.c
index 9558b3f..ac373aa 100644
--- a/src/trau_frame.c
+++ b/src/trau_frame.c
@@ -85,6 +85,7 @@
 	memcpy(fr->t_bits+0, trau_bits+316, 4);
 	/* D1 .. D5 */
 	memcpy(fr->d_bits, trau_bits+43, 5);
+	d_idx += 5;
 	/* D6 .. D245 */
 	for (i = 48; i < 304; i += 16) {
 		memcpy(fr->d_bits + d_idx, trau_bits+i+1, 15);