diff --git a/src/apps/monero/xmr/bulletproof.py b/src/apps/monero/xmr/bulletproof.py
index bc044a83c..1e7a6457c 100644
--- a/src/apps/monero/xmr/bulletproof.py
+++ b/src/apps/monero/xmr/bulletproof.py
@@ -1302,11 +1302,11 @@ def _prove_batch_main(self, V, gamma, aL, aR, hash_cache, logM, logN, M, N):
         del (rho, alpha)
 
         # PAPER LINES 54-57
-        l = vector_add(l0, vector_scalar(l1, x), l0)
+        l = vector_add(l0, KeyVEval(len(l1), lambda i, d: sc_mul(d, l1[i], x)), l0)
         del (l1, sL)
         self.gc(19)
 
-        r = vector_add(r0, vector_scalar(r1, x), r0)
+        r = vector_add(r0, vector_scalar(r1, x, r1), r0)
         t = inner_product(l, r)
         del (r1)
         self.gc(19)