diff --git a/src/test/blockencodings_tests.cpp b/src/test/blockencodings_tests.cpp
index 3884bf3fe..d2392cfb2 100644
--- a/src/test/blockencodings_tests.cpp
+++ b/src/test/blockencodings_tests.cpp
@@ -283,7 +283,6 @@ BOOST_AUTO_TEST_CASE(EmptyBlockRoundTripTest)
         std::vector<CTransaction> vtx_missing;
         BOOST_CHECK(partialBlock.FillBlock(block2, vtx_missing) == READ_STATUS_OK);
         BOOST_CHECK_EQUAL(block.GetHash().ToString(), block2.GetHash().ToString());
-        bool mutated;
         BOOST_CHECK_EQUAL(block.hashMerkleRoot.ToString(), BlockMerkleRoot(block2, &mutated).ToString());
         BOOST_CHECK(!mutated);
     }