diff --git a/src/ripple/app/ledger/LedgerMaster.cpp b/src/ripple/app/ledger/LedgerMaster.cpp
index ee7b95dee..4a8b07fea 100644
--- a/src/ripple/app/ledger/LedgerMaster.cpp
+++ b/src/ripple/app/ledger/LedgerMaster.cpp
@@ -394,8 +394,9 @@ public:
         }
         if (didApply)
         {
-           mCurrentLedger.set (ledger);
-           getApp().getOPs ().pubProposedTransaction (ledger, txn, result);
+            ledger->setImmutable (); // So the next line doesn't have to copy
+            mCurrentLedger.set (ledger);
+            getApp().getOPs ().pubProposedTransaction (ledger, txn, result);
         }
         return result;
     }
diff --git a/src/ripple/app/main/Application.cpp b/src/ripple/app/main/Application.cpp
index 3e70418eb..6cff83eac 100644
--- a/src/ripple/app/main/Application.cpp
+++ b/src/ripple/app/main/Application.cpp
@@ -1084,6 +1084,7 @@ void ApplicationImp::startNewLedger ()
         firstLedger->updateHash ();
         firstLedger->setClosed ();
         firstLedger->setAccepted ();
+        firstLedger->setImmutable();
         m_ledgerMaster->pushLedger (firstLedger);
 
         Ledger::pointer secondLedger = std::make_shared<Ledger> (true, std::ref (*firstLedger));
diff --git a/src/ripple/shamap/SHAMap.h b/src/ripple/shamap/SHAMap.h
index c97cb18fe..2fac043b8 100644
--- a/src/ripple/shamap/SHAMap.h
+++ b/src/ripple/shamap/SHAMap.h
@@ -274,6 +274,7 @@ void
 SHAMap::setImmutable ()
 {
     assert (state_ != SHAMapState::Invalid);
+    unshare ();
     state_ = SHAMapState::Immutable;
 }
 
diff --git a/src/ripple/shamap/impl/SHAMap.cpp b/src/ripple/shamap/impl/SHAMap.cpp
index e043e5662..962ae1207 100644
--- a/src/ripple/shamap/impl/SHAMap.cpp
+++ b/src/ripple/shamap/impl/SHAMap.cpp
@@ -75,7 +75,7 @@ SHAMap::snapShot (bool isMutable) const
     newMap.seq_ = seq_ + 1;
     newMap.root_ = root_;
 
-    if ((state_ != SHAMapState::Immutable) || !isMutable)
+    if ((state_ != SHAMapState::Immutable) || isMutable)
     {
         // If either map may change, they cannot share nodes
         newMap.unshare ();