diff --git a/specs/light_client/merkle_proofs.md b/specs/light_client/merkle_proofs.md
index 038990709..2e00806ee 100644
--- a/specs/light_client/merkle_proofs.md
+++ b/specs/light_client/merkle_proofs.md
@@ -259,7 +259,7 @@ def verify_merkle_multiproof(leaves: Sequence[Hash], proof: Sequence[Hash], indi
     while pos < len(keys):
         k = keys[pos]
         if k in objects and k ^ 1 in objects and k // 2 not in objects:
-            objects[k // 2] = hash(objects[k & -2] + objects[k | 1])
+            objects[k // 2] = hash(objects[(k | 1) ^ 1] + objects[k | 1])
             keys.append(k // 2)
         pos += 1
     return objects[1] == root