diff --git a/newcoin.vcxproj b/newcoin.vcxproj
index fbd79cb56..dfaccea23 100644
--- a/newcoin.vcxproj
+++ b/newcoin.vcxproj
@@ -175,6 +175,7 @@
     <ClCompile Include="src\cpp\ripple\Suppression.cpp" />
     <ClCompile Include="src\cpp\ripple\Transaction.cpp" />
     <ClCompile Include="src\cpp\ripple\TransactionAcquire.cpp" />
+    <ClCompile Include="src\cpp\ripple\TransactionCheck.cpp" />
     <ClCompile Include="src\cpp\ripple\TransactionEngine.cpp" />
     <ClCompile Include="src\cpp\ripple\TransactionErr.cpp" />
     <ClCompile Include="src\cpp\ripple\TransactionFormats.cpp" />
diff --git a/newcoin.vcxproj.filters b/newcoin.vcxproj.filters
index 961347ae6..2ccbac5b4 100644
--- a/newcoin.vcxproj.filters
+++ b/newcoin.vcxproj.filters
@@ -249,6 +249,9 @@
     <ClCompile Include="src\cpp\ripple\TransactionEngine.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="src\cpp\ripple\TransactionCheck.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="src\cpp\ripple\TransactionErr.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
diff --git a/ripple2010.vcxproj b/ripple2010.vcxproj
index 843c6f9dc..d3e9aff5c 100644
--- a/ripple2010.vcxproj
+++ b/ripple2010.vcxproj
@@ -175,6 +175,7 @@
     <ClCompile Include="src\cpp\ripple\Suppression.cpp" />
     <ClCompile Include="src\cpp\ripple\Transaction.cpp" />
     <ClCompile Include="src\cpp\ripple\TransactionAcquire.cpp" />
+    <ClCompile Include="src\cpp\ripple\TransactionCheck.cpp" />
     <ClCompile Include="src\cpp\ripple\TransactionEngine.cpp" />
     <ClCompile Include="src\cpp\ripple\TransactionErr.cpp" />
     <ClCompile Include="src\cpp\ripple\TransactionFormats.cpp" />
diff --git a/ripple2010.vcxproj.filters b/ripple2010.vcxproj.filters
index 0ef380379..bbdf82255 100644
--- a/ripple2010.vcxproj.filters
+++ b/ripple2010.vcxproj.filters
@@ -243,6 +243,9 @@
     <ClCompile Include="src\cpp\ripple\TransactionAcquire.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="src\cpp\ripple\TransactionCheck.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="src\cpp\ripple\TransactionEngine.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
diff --git a/src/cpp/ripple/TransactionCheck.cpp b/src/cpp/ripple/TransactionCheck.cpp
new file mode 100644
index 000000000..50b1a7f7c
--- /dev/null
+++ b/src/cpp/ripple/TransactionCheck.cpp
@@ -0,0 +1,11 @@
+
+#include "TransactionErr.h"
+#include "TransactionEngine.h"
+
+// Double check a transaction's metadata to make sure no system invariants were broken
+// Call right before 'calcRawMeta'
+
+bool TransactionEngine::checkInvariants(TER result, const SerializedTransaction& txn, TransactionEngineParams params)
+{
+	return true;
+}
diff --git a/src/cpp/ripple/TransactionEngine.cpp b/src/cpp/ripple/TransactionEngine.cpp
index 1e0beac41..79ce67c1f 100644
--- a/src/cpp/ripple/TransactionEngine.cpp
+++ b/src/cpp/ripple/TransactionEngine.cpp
@@ -93,7 +93,7 @@ TER TransactionEngine::applyTransaction(const SerializedTransaction& txn, Transa
 	}
 #endif
 
-	UPTR_T<Transactor> transactor = Transactor::makeTransactor(txn,params,this);
+	UPTR_T<Transactor> transactor = Transactor::makeTransactor(txn, params, this);
 	if (transactor.get() != NULL)
 	{
 		uint256 txID		= txn.getTransactionID();
@@ -153,28 +153,39 @@ TER TransactionEngine::applyTransaction(const SerializedTransaction& txn, Transa
 
 		if (didApply)
 		{
-			// Transaction succeeded fully or (retries are not allowed and the transaction could claim a fee)
-			Serializer m;
-			mNodes.calcRawMeta(m, terResult, mTxnSeq++);
-
-			txnWrite();
-
-			Serializer s;
-			txn.add(s);
-
-			if (isSetBit(params, tapOPEN_LEDGER))
+			if (!checkInvariants(terResult, txn, params))
 			{
-				if (!mLedger->addTransaction(txID, s))
-					assert(false);
+				cLog(lsFATAL) << "Transaction violates invariants";
+				cLog(lsFATAL) << txn.getJson(0);
+				cLog(lsFATAL) << transToken(terResult) << ": " << transHuman(terResult);
+				cLog(lsFATAL) << mNodes.getJson(0);
+				didApply = false;
 			}
 			else
 			{
-				if (!mLedger->addTransaction(txID, s, m))
+				// Transaction succeeded fully or (retries are not allowed and the transaction could claim a fee)
+				Serializer m;
+				mNodes.calcRawMeta(m, terResult, mTxnSeq++);
+
+				txnWrite();
+
+				Serializer s;
+				txn.add(s);
+
+				if (isSetBit(params, tapOPEN_LEDGER))
+				{
+					if (!mLedger->addTransaction(txID, s))
+						assert(false);
+				}
+				else
+				{
+					if (!mLedger->addTransaction(txID, s, m))
 					assert(false);
 
-				// Charge whatever fee they specified.
-				STAmount saPaid = txn.getTransactionFee();
-				mLedger->destroyCoins(saPaid.getNValue());
+					// Charge whatever fee they specified.
+					STAmount saPaid = txn.getTransactionFee();
+					mLedger->destroyCoins(saPaid.getNValue());
+				}
 			}
 		}
 
diff --git a/src/cpp/ripple/TransactionEngine.h b/src/cpp/ripple/TransactionEngine.h
index 2ad074efb..17e1e02f9 100644
--- a/src/cpp/ripple/TransactionEngine.h
+++ b/src/cpp/ripple/TransactionEngine.h
@@ -65,6 +65,7 @@ public:
 	void				entryModify(SLE::ref sleEntry)								{ mNodes.entryModify(sleEntry); }
 
 	TER applyTransaction(const SerializedTransaction&, TransactionEngineParams, bool& didApply);
+	bool checkInvariants(TER result, const SerializedTransaction& txn, TransactionEngineParams params);
 };
 
 inline TransactionEngineParams operator|(const TransactionEngineParams& l1, const TransactionEngineParams& l2)