diff --git a/src/bench/merkle_root.cpp b/src/bench/merkle_root.cpp
index 5be592707ff..0e4c779f142 100644
--- a/src/bench/merkle_root.cpp
+++ b/src/bench/merkle_root.cpp
@@ -24,9 +24,9 @@ static void MerkleRoot(benchmark::Bench& bench)
     for (bool mutate : {false, true}) {
         bench.name(mutate ? "MerkleRootWithMutation" : "MerkleRoot").batch(hashes.size()).unit("leaf").run([&] {
             std::vector<uint256> leaves;
-            leaves.resize(hashes.size());
+            leaves.reserve((hashes.size() + 1) & ~1ULL); // capacity rounded up to even
             for (size_t s = 0; s < hashes.size(); s++) {
-                leaves[s] = hashes[s];
+                leaves.push_back(hashes[s]);
             }
 
             bool mutated{false};
diff --git a/src/consensus/merkle.cpp b/src/consensus/merkle.cpp
index 703a824e16f..b0819a1763e 100644
--- a/src/consensus/merkle.cpp
+++ b/src/consensus/merkle.cpp
@@ -66,9 +66,9 @@ uint256 ComputeMerkleRoot(std::vector<uint256> hashes, bool* mutated) {
 uint256 BlockMerkleRoot(const CBlock& block, bool* mutated)
 {
     std::vector<uint256> leaves;
-    leaves.resize(block.vtx.size());
+    leaves.reserve((block.vtx.size() + 1) & ~1ULL); // capacity rounded up to even
     for (size_t s = 0; s < block.vtx.size(); s++) {
-        leaves[s] = block.vtx[s]->GetHash().ToUint256();
+        leaves.push_back(block.vtx[s]->GetHash().ToUint256());
     }
     return ComputeMerkleRoot(std::move(leaves), mutated);
 }
@@ -76,10 +76,10 @@ uint256 BlockMerkleRoot(const CBlock& block, bool* mutated)
 uint256 BlockWitnessMerkleRoot(const CBlock& block)
 {
     std::vector<uint256> leaves;
-    leaves.resize(block.vtx.size());
-    leaves[0].SetNull(); // The witness hash of the coinbase is 0.
+    leaves.reserve((block.vtx.size() + 1) & ~1ULL); // capacity rounded up to even
+    leaves.emplace_back(); // The witness hash of the coinbase is 0.
     for (size_t s = 1; s < block.vtx.size(); s++) {
-        leaves[s] = block.vtx[s]->GetWitnessHash().ToUint256();
+        leaves.push_back(block.vtx[s]->GetWitnessHash().ToUint256());
     }
     return ComputeMerkleRoot(std::move(leaves));
 }
diff --git a/src/signet.cpp b/src/signet.cpp
index 6524ebff45e..6c1df371aa9 100644
--- a/src/signet.cpp
+++ b/src/signet.cpp
@@ -58,10 +58,10 @@ static bool FetchAndClearCommitmentSection(const std::span<const uint8_t> header
 static uint256 ComputeModifiedMerkleRoot(const CMutableTransaction& cb, const CBlock& block)
 {
     std::vector<uint256> leaves;
-    leaves.resize(block.vtx.size());
-    leaves[0] = cb.GetHash().ToUint256();
+    leaves.reserve((block.vtx.size() + 1) & ~1ULL); // capacity rounded up to even
+    leaves.push_back(cb.GetHash().ToUint256());
     for (size_t s = 1; s < block.vtx.size(); ++s) {
-        leaves[s] = block.vtx[s]->GetHash().ToUint256();
+        leaves.push_back(block.vtx[s]->GetHash().ToUint256());
     }
     return ComputeMerkleRoot(std::move(leaves));
 }