diff --git a/poc/vdaf_pine.py b/poc/vdaf_pine.py
index 22465c6..9d8816d 100644
--- a/poc/vdaf_pine.py
+++ b/poc/vdaf_pine.py
@@ -299,7 +299,7 @@ def prep_init(Pine,
             Pine.joint_rand_part_and_seed_for_aggregator(
                 agg_id,
                 k_wr_joint_rand_blind,
-                meas_share[:Pine.Flp.Valid.encoded_gradient_len],
+                meas_share[:Pine.Flp.Valid.encoded_gradient_and_norm_len],
                 nonce,
                 k_wr_joint_rand_parts,
                 USAGE_WR_JOINT_RAND_PART,