diff --git a/src/main.cpp b/src/main.cpp
index fca12b7cb..adc4ac0d2 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3260,6 +3260,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
                         if (pfrom->pfilter)
                         {
                             CMerkleBlock merkleBlock(block, *pfrom->pfilter);
+                            pfrom->PushMessage("merkleblock", merkleBlock);
                             // CMerkleBlock just contains hashes, so also push any transactions in the block the client did not see 
                             // This avoids hurting performance by pointlessly requiring a round-trip
                             // Note that there is currently no way for a node to request any single transactions we didnt send here -
@@ -3270,7 +3271,6 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
                             BOOST_FOREACH(PairType& pair, merkleBlock.vMatchedTxn)
                                 if (!pfrom->setInventoryKnown.count(CInv(MSG_TX, pair.second)))
                                     pfrom->PushMessage("tx", block.vtx[pair.first]);
-                            pfrom->PushMessage("merkleblock", merkleBlock);
                         }
                         // else
                             // no response
@@ -3581,7 +3581,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
 
         // Nodes must NEVER send a data item > 520 bytes (the max size for a script data object,
         // and thus, the maximum size any matched object can have) in a filteradd message
-        if (vData.size() > 520)
+        if (vData.size() > MAX_SCRIPT_ELEMENT_SIZE)
         {
             pfrom->Misbehaving(100);
         } else {
diff --git a/src/script.cpp b/src/script.cpp
index 70adf1f9d..45ac8335d 100644
--- a/src/script.cpp
+++ b/src/script.cpp
@@ -340,7 +340,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
             //
             if (!script.GetOp(pc, opcode, vchPushValue))
                 return false;
-            if (vchPushValue.size() > 520)
+            if (vchPushValue.size() > MAX_SCRIPT_ELEMENT_SIZE)
                 return false;
             if (opcode > OP_16 && ++nOpCount > 201)
                 return false;
@@ -670,7 +670,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     valtype& vch2 = stacktop(-1);
                     vch1.insert(vch1.end(), vch2.begin(), vch2.end());
                     popstack(stack);
-                    if (stacktop(-1).size() > 520)
+                    if (stacktop(-1).size() > MAX_SCRIPT_ELEMENT_SIZE)
                         return false;
                 }
                 break;
diff --git a/src/script.h b/src/script.h
index 0b481eb60..4b29f6273 100644
--- a/src/script.h
+++ b/src/script.h
@@ -17,6 +17,8 @@
 class CCoins;
 class CTransaction;
 
+static const unsigned int MAX_SCRIPT_ELEMENT_SIZE = 520; // bytes
+
 /** Signature hash types/flags */
 enum
 {