diff --git a/src/rest.cpp b/src/rest.cpp
index 6ba15172f..779284499 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -157,13 +157,13 @@ static bool rest_headers(HTTPRequest* req,
         }
     }
 
-    CDataStream ssHeader(SER_NETWORK, PROTOCOL_VERSION);
-    for (const CBlockIndex *pindex : headers) {
-        ssHeader << pindex->GetBlockHeader();
-    }
-
     switch (rf) {
     case RetFormat::BINARY: {
+        CDataStream ssHeader(SER_NETWORK, PROTOCOL_VERSION);
+        for (const CBlockIndex *pindex : headers) {
+            ssHeader << pindex->GetBlockHeader();
+        }
+
         std::string binaryHeader = ssHeader.str();
         req->WriteHeader("Content-Type", "application/octet-stream");
         req->WriteReply(HTTP_OK, binaryHeader);
@@ -171,6 +171,11 @@ static bool rest_headers(HTTPRequest* req,
     }
 
     case RetFormat::HEX: {
+        CDataStream ssHeader(SER_NETWORK, PROTOCOL_VERSION);
+        for (const CBlockIndex *pindex : headers) {
+            ssHeader << pindex->GetBlockHeader();
+        }
+
         std::string strHex = HexStr(ssHeader.begin(), ssHeader.end()) + "\n";
         req->WriteHeader("Content-Type", "text/plain");
         req->WriteReply(HTTP_OK, strHex);
@@ -224,11 +229,10 @@ static bool rest_block(HTTPRequest* req,
             return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not found");
     }
 
-    CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
-    ssBlock << block;
-
     switch (rf) {
     case RetFormat::BINARY: {
+        CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
+        ssBlock << block;
         std::string binaryBlock = ssBlock.str();
         req->WriteHeader("Content-Type", "application/octet-stream");
         req->WriteReply(HTTP_OK, binaryBlock);
@@ -236,6 +240,8 @@ static bool rest_block(HTTPRequest* req,
     }
 
     case RetFormat::HEX: {
+        CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
+        ssBlock << block;
         std::string strHex = HexStr(ssBlock.begin(), ssBlock.end()) + "\n";
         req->WriteHeader("Content-Type", "text/plain");
         req->WriteReply(HTTP_OK, strHex);
@@ -360,11 +366,11 @@ static bool rest_tx(HTTPRequest* req, const std::string& strURIPart)
     if (!GetTransaction(hash, tx, Params().GetConsensus(), hashBlock, true))
         return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not found");
 
-    CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
-    ssTx << tx;
-
     switch (rf) {
     case RetFormat::BINARY: {
+        CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
+        ssTx << tx;
+
         std::string binaryTx = ssTx.str();
         req->WriteHeader("Content-Type", "application/octet-stream");
         req->WriteReply(HTTP_OK, binaryTx);
@@ -372,6 +378,9 @@ static bool rest_tx(HTTPRequest* req, const std::string& strURIPart)
     }
 
     case RetFormat::HEX: {
+        CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
+        ssTx << tx;
+
         std::string strHex = HexStr(ssTx.begin(), ssTx.end()) + "\n";
         req->WriteHeader("Content-Type", "text/plain");
         req->WriteReply(HTTP_OK, strHex);