diff --git a/src/xrpld/app/ledger/detail/TransactionAcquire.cpp b/src/xrpld/app/ledger/detail/TransactionAcquire.cpp
index c165d69e2a..149096e393 100644
--- a/src/xrpld/app/ledger/detail/TransactionAcquire.cpp
+++ b/src/xrpld/app/ledger/detail/TransactionAcquire.cpp
@@ -174,7 +174,7 @@ TransactionAcquire::trigger(std::shared_ptr<Peer> const& peer)
 
 SHAMapAddNode
 TransactionAcquire::takeNodes(
-    std::vector<std::pair<SHAMapNodeID, intr_ptr::SharedPtr<SHAMapTreeNode>>>& data,
+    std::vector<std::pair<SHAMapNodeID, intr_ptr::SharedPtr<SHAMapTreeNode>>> data,
     std::shared_ptr<Peer> const& peer)
 {
     ScopedLockType const sl(mtx_);
diff --git a/src/xrpld/app/ledger/detail/TransactionAcquire.h b/src/xrpld/app/ledger/detail/TransactionAcquire.h
index ac51805c1b..9a594f4de7 100644
--- a/src/xrpld/app/ledger/detail/TransactionAcquire.h
+++ b/src/xrpld/app/ledger/detail/TransactionAcquire.h
@@ -21,7 +21,7 @@ public:
 
     SHAMapAddNode
     takeNodes(
-        std::vector<std::pair<SHAMapNodeID, intr_ptr::SharedPtr<SHAMapTreeNode>>>& data,
+        std::vector<std::pair<SHAMapNodeID, intr_ptr::SharedPtr<SHAMapTreeNode>>> data,
         std::shared_ptr<Peer> const& peer);
 
     void