diff --git a/src/BtDependency.cc b/src/BtDependency.cc
index 967fa845..a952feae 100644
--- a/src/BtDependency.cc
+++ b/src/BtDependency.cc
@@ -100,7 +100,7 @@ bool BtDependency::resolve()
         dependee->getPieceStorage()->getDiskAdaptor();
       diskAdaptor->openExistingFile();
       std::string content = util::toString(diskAdaptor);
-      if(dependee->getDownloadContext()->hasAttribute(bittorrent::BITTORRENT)) {
+      if(dependee->getDownloadContext()->hasAttribute(CTX_ATTR_BT)) {
         SharedHandle<TorrentAttribute> attrs =
           bittorrent::getTorrentAttrs(dependee->getDownloadContext());
         bittorrent::loadFromMemory
diff --git a/src/BtSetup.cc b/src/BtSetup.cc
index d49b5985..cd975762 100644
--- a/src/BtSetup.cc
+++ b/src/BtSetup.cc
@@ -94,7 +94,7 @@ void BtSetup::setup(std::vector<Command*>& commands,
                     DownloadEngine* e,
                     const Option* option)
 {
-  if(!requestGroup->getDownloadContext()->hasAttribute(bittorrent::BITTORRENT)){
+  if(!requestGroup->getDownloadContext()->hasAttribute(CTX_ATTR_BT)){
     return;
   }
   SharedHandle<TorrentAttribute> torrentAttrs =
diff --git a/src/ConsoleStatCalc.cc b/src/ConsoleStatCalc.cc
index 735a6a84..95e569e5 100644
--- a/src/ConsoleStatCalc.cc
+++ b/src/ConsoleStatCalc.cc
@@ -110,7 +110,7 @@ void printProgress
     << "#" << rg->getGID() << " ";
 
 #ifdef ENABLE_BITTORRENT
-  if(rg->getDownloadContext()->hasAttribute(bittorrent::BITTORRENT) &&
+  if(rg->getDownloadContext()->hasAttribute(CTX_ATTR_BT) &&
      !bittorrent::getTorrentAttrs(rg->getDownloadContext())->metadata.empty() &&
      rg->downloadFinished()) {
     o << "SEEDING" << "(" << "ratio:";
diff --git a/src/ContextAttribute.cc b/src/ContextAttribute.cc
new file mode 100644
index 00000000..b106903e
--- /dev/null
+++ b/src/ContextAttribute.cc
@@ -0,0 +1,49 @@
+/* <!-- copyright */
+/*
+ * aria2 - The high speed download utility
+ *
+ * Copyright (C) 2012 Tatsuhiro Tsujikawa
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to link the code of portions of this program with the
+ * OpenSSL library under certain conditions as described in each
+ * individual source file, and distribute linked combinations
+ * including the two.
+ * You must obey the GNU General Public License in all respects
+ * for all of the code used other than OpenSSL.  If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so.  If you
+ * do not wish to do so, delete this exception statement from your
+ * version.  If you delete this exception statement from all source
+ * files in the program, then also delete it here.
+ */
+/* copyright --> */
+#include "ContextAttribute.h"
+
+namespace aria2 {
+
+const char* strContextAttributeType(ContextAttributeType key)
+{
+  switch(key) {
+  case CTX_ATTR_BT:
+    return "BitTorrent";
+  default:
+    return "UNKNOWN";
+  }
+}
+
+} // namespace aria2
diff --git a/src/ContextAttribute.h b/src/ContextAttribute.h
index 02bda128..10b9f129 100644
--- a/src/ContextAttribute.h
+++ b/src/ContextAttribute.h
@@ -43,6 +43,17 @@ struct ContextAttribute {
   virtual ~ContextAttribute() {}
 };
 
+enum ContextAttributeType {
+  // For BitTorrent
+  CTX_ATTR_BT,
+  // Max value of attribute type to use allocate vector to hold
+  // attributes.
+  MAX_CTX_ATTR
+};
+
+// Returns human readable string representation of type |key|
+const char* strContextAttributeType(ContextAttributeType key);
+
 } // namespace aria2
 
 #endif // D_CONTEXT_ATTRIBUTE_H
diff --git a/src/DefaultPieceStorage.cc b/src/DefaultPieceStorage.cc
index 9dcb154b..a59a20a1 100644
--- a/src/DefaultPieceStorage.cc
+++ b/src/DefaultPieceStorage.cc
@@ -465,7 +465,7 @@ void DefaultPieceStorage::completePiece(const SharedHandle<Piece>& piece)
       A2_LOG_INFO(MSG_DOWNLOAD_COMPLETED);
     }
 #ifdef ENABLE_BITTORRENT
-    if(downloadContext_->hasAttribute(bittorrent::BITTORRENT)) {
+    if(downloadContext_->hasAttribute(CTX_ATTR_BT)) {
       SharedHandle<TorrentAttribute> torrentAttrs =
         bittorrent::getTorrentAttrs(downloadContext_);
       if(!torrentAttrs->metadata.empty()) {
diff --git a/src/DownloadCommand.cc b/src/DownloadCommand.cc
index 45671be6..2ed595b5 100644
--- a/src/DownloadCommand.cc
+++ b/src/DownloadCommand.cc
@@ -227,7 +227,7 @@ bool DownloadCommand::executeInternal() {
           if(
 #ifdef ENABLE_BITTORRENT
              (!getPieceStorage()->isEndGame() ||
-              !getDownloadContext()->hasAttribute(bittorrent::BITTORRENT)) &&
+              !getDownloadContext()->hasAttribute(CTX_ATTR_BT)) &&
 #endif // ENABLE_BITTORRENT
              segment->isHashCalculated()) {
             A2_LOG_DEBUG(fmt("Hash is available! index=%lu",
diff --git a/src/DownloadContext.cc b/src/DownloadContext.cc
index 10c03ca6..16ddd159 100644
--- a/src/DownloadContext.cc
+++ b/src/DownloadContext.cc
@@ -43,7 +43,6 @@
 #include "DlAbortEx.h"
 #include "a2functional.h"
 #include "Signature.h"
-#include "ContextAttribute.h"
 
 namespace aria2 {
 
@@ -52,6 +51,7 @@ DownloadContext::DownloadContext():
   checksumVerified_(false),
   knowsTotalLength_(true),
   ownerRequestGroup_(0),
+  attrs_(MAX_CTX_ATTR),
   downloadStartTime_(0),
   downloadStopTime_(downloadStartTime_),
   metalinkServerContacted_(false) {}
@@ -63,6 +63,7 @@ DownloadContext::DownloadContext(int32_t pieceLength,
   checksumVerified_(false),
   knowsTotalLength_(true),
   ownerRequestGroup_(0),
+  attrs_(MAX_CTX_ATTR),
   downloadStartTime_(0),
   downloadStopTime_(0),
   metalinkServerContacted_(false)
@@ -151,32 +152,29 @@ void DownloadContext::setFileFilter(SegList<int>& sgl)
 }
 
 void DownloadContext::setAttribute
-(const std::string& key, const SharedHandle<ContextAttribute>& value)
+(ContextAttributeType key, const SharedHandle<ContextAttribute>& value)
 {
-  std::map<std::string, SharedHandle<ContextAttribute> >::value_type p =
-    std::make_pair(key, value);
-  std::pair<std::map<std::string, SharedHandle<ContextAttribute> >::iterator,
-            bool> r = attrs_.insert(p);
-  if(!r.second) {
-    (*r.first).second = value;
-  }
+  assert(key < MAX_CTX_ATTR);
+  attrs_[key] = value;
 }
 
 const SharedHandle<ContextAttribute>& DownloadContext::getAttribute
-(const std::string& key)
+(ContextAttributeType key)
 {
-  std::map<std::string, SharedHandle<ContextAttribute> >::const_iterator itr =
-    attrs_.find(key);
-  if(itr == attrs_.end()) {
-    throw DL_ABORT_EX(fmt("No attribute named %s", key.c_str()));
+  assert(key < MAX_CTX_ATTR);
+  const SharedHandle<ContextAttribute>& attr = attrs_[key];
+  if(attr) {
+    return attr;
   } else {
-    return (*itr).second;
+    throw DL_ABORT_EX(fmt("No attribute named %s",
+                          strContextAttributeType(key)));
   }
 }
 
-bool DownloadContext::hasAttribute(const std::string& key) const
+bool DownloadContext::hasAttribute(ContextAttributeType key) const
 {
-  return attrs_.count(key) == 1;
+  assert(key < MAX_CTX_ATTR);
+  return attrs_[key];
 }
 
 void DownloadContext::releaseRuntimeResource()
diff --git a/src/DownloadContext.h b/src/DownloadContext.h
index 810671bd..29d4840a 100644
--- a/src/DownloadContext.h
+++ b/src/DownloadContext.h
@@ -46,13 +46,13 @@
 #include "A2STR.h"
 #include "ValueBase.h"
 #include "SegList.h"
+#include "ContextAttribute.h"
 
 namespace aria2 {
 
 class RequestGroup;
 class Signature;
 class FileEntry;
-struct ContextAttribute;
 
 class DownloadContext
 {
@@ -77,7 +77,7 @@ private:
 
   RequestGroup* ownerRequestGroup_;
   
-  std::map<std::string, SharedHandle<ContextAttribute> > attrs_;
+  std::vector<SharedHandle<ContextAttribute> > attrs_;
 
   Timer downloadStartTime_;
 
@@ -203,11 +203,11 @@ public:
   }
 
   void setAttribute
-  (const std::string& key, const SharedHandle<ContextAttribute>& value);
+  (ContextAttributeType key, const SharedHandle<ContextAttribute>& value);
 
-  const SharedHandle<ContextAttribute>& getAttribute(const std::string& key);
+  const SharedHandle<ContextAttribute>& getAttribute(ContextAttributeType key);
 
-  bool hasAttribute(const std::string& key) const;
+  bool hasAttribute(ContextAttributeType key) const;
 
   void resetDownloadStartTime();
 
diff --git a/src/Makefile.am b/src/Makefile.am
index b04d78c6..a4a88790 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -189,7 +189,7 @@ SRCS =  Socket.h\
 	Event.h\
 	timespec.h\
 	ValueBase.cc ValueBase.h\
-	ContextAttribute.h\
+	ContextAttribute.cc ContextAttribute.h\
 	TorrentAttribute.cc TorrentAttribute.h\
 	AdaptiveFileAllocationIterator.cc AdaptiveFileAllocationIterator.h\
 	TruncFileAllocationIterator.cc TruncFileAllocationIterator.h\
diff --git a/src/RequestGroup.cc b/src/RequestGroup.cc
index 4f55ee2e..6b95beab 100644
--- a/src/RequestGroup.cc
+++ b/src/RequestGroup.cc
@@ -283,7 +283,7 @@ void RequestGroup::createInitialCommand
   downloadContext_->resetDownloadStartTime();
 #ifdef ENABLE_BITTORRENT
   {
-    if(downloadContext_->hasAttribute(bittorrent::BITTORRENT)) {
+    if(downloadContext_->hasAttribute(CTX_ATTR_BT)) {
       SharedHandle<TorrentAttribute> torrentAttrs =
         bittorrent::getTorrentAttrs(downloadContext_);
       bool metadataGetMode = torrentAttrs->metadata.empty();
@@ -584,14 +584,14 @@ void RequestGroup::initPieceStorage()
      // content-length = 0. Google's dl server used this before.
      (downloadContext_->getTotalLength() > 0
 #ifdef ENABLE_BITTORRENT
-      || downloadContext_->hasAttribute(bittorrent::BITTORRENT)
+      || downloadContext_->hasAttribute(CTX_ATTR_BT)
 #endif // ENABLE_BITTORRENT
       )) {
 #ifdef ENABLE_BITTORRENT
     DefaultPieceStorage* ps =
       new DefaultPieceStorage(downloadContext_, option_.get());
     SharedHandle<PieceStorage> psHolder(ps);
-    if(downloadContext_->hasAttribute(bittorrent::BITTORRENT)) {
+    if(downloadContext_->hasAttribute(CTX_ATTR_BT)) {
       if(isUriSuppliedForRequsetFileEntry
          (downloadContext_->getFileEntries().begin(),
           downloadContext_->getFileEntries().end())) {
@@ -1179,7 +1179,7 @@ DownloadResultHandle RequestGroup::createDownloadResult() const
     }
   }
 #ifdef ENABLE_BITTORRENT
-  if(downloadContext_->hasAttribute(bittorrent::BITTORRENT)) {
+  if(downloadContext_->hasAttribute(CTX_ATTR_BT)) {
     const unsigned char* p = bittorrent::getInfoHash(downloadContext_);
     res->infoHash.assign(p, p+INFO_HASH_LENGTH);
   }
@@ -1196,7 +1196,7 @@ void RequestGroup::reportDownloadFinished()
                     downloadContext_->getBasePath().c_str()));
   uriSelector_->resetCounters();
 #ifdef ENABLE_BITTORRENT
-  if(downloadContext_->hasAttribute(bittorrent::BITTORRENT)) {
+  if(downloadContext_->hasAttribute(CTX_ATTR_BT)) {
     TransferStat stat = calculateStat();
     int64_t completedLength = getCompletedLength();
     double shareRatio = completedLength == 0 ? 0.0 :
@@ -1309,7 +1309,7 @@ void RequestGroup::setDownloadContext
 bool RequestGroup::p2pInvolved() const
 {
 #ifdef ENABLE_BITTORRENT
-  return downloadContext_->hasAttribute(bittorrent::BITTORRENT);
+  return downloadContext_->hasAttribute(CTX_ATTR_BT);
 #else // !ENABLE_BITTORRENT
   return false;
 #endif // !ENABLE_BITTORRENT
diff --git a/src/RequestGroupMan.cc b/src/RequestGroupMan.cc
index 19262793..4206aac9 100644
--- a/src/RequestGroupMan.cc
+++ b/src/RequestGroupMan.cc
@@ -423,7 +423,7 @@ public:
           // we don't remove it.
           if(group->getOption()->getAsBool(PREF_BT_REMOVE_UNSELECTED_FILE) &&
              !group->inMemoryDownload() &&
-             dctx->hasAttribute(bittorrent::BITTORRENT)) {
+             dctx->hasAttribute(CTX_ATTR_BT)) {
             A2_LOG_INFO(fmt(MSG_REMOVING_UNSELECTED_FILE, group->getGID()));
             const std::vector<SharedHandle<FileEntry> >& files =
               dctx->getFileEntries();
diff --git a/src/RpcMethodImpl.cc b/src/RpcMethodImpl.cc
index ee421812..32c362e3 100644
--- a/src/RpcMethodImpl.cc
+++ b/src/RpcMethodImpl.cc
@@ -801,7 +801,7 @@ void gatherProgress
 {
   gatherProgressCommon(entryDict, group, keys);
 #ifdef ENABLE_BITTORRENT
-  if(group->getDownloadContext()->hasAttribute(bittorrent::BITTORRENT)) {
+  if(group->getDownloadContext()->hasAttribute(CTX_ATTR_BT)) {
     SharedHandle<TorrentAttribute> torrentAttrs =
       bittorrent::getTorrentAttrs(group->getDownloadContext());
     const SharedHandle<BtObject>& btObject =
@@ -1117,7 +1117,7 @@ void changeOption
   if(option.defined(PREF_DIR) || option.defined(PREF_OUT)) {
     if(dctx->getFileEntries().size() == 1
 #ifdef ENABLE_BITTORRENT
-       && !dctx->hasAttribute(bittorrent::BITTORRENT)
+       && !dctx->hasAttribute(CTX_ATTR_BT)
 #endif // ENABLE_BITTORRENT
        ) {
       dctx->getFirstFileEntry()->setPath
@@ -1127,7 +1127,7 @@ void changeOption
   }
 #ifdef ENABLE_BITTORRENT
   if(option.defined(PREF_DIR) || option.defined(PREF_INDEX_OUT)) {
-    if(dctx->hasAttribute(bittorrent::BITTORRENT)) {
+    if(dctx->hasAttribute(CTX_ATTR_BT)) {
       std::istringstream indexOutIn(grOption->get(PREF_INDEX_OUT));
       std::vector<std::pair<size_t, std::string> > indexPaths =
         util::createIndexPaths(indexOutIn);
diff --git a/src/UTMetadataPostDownloadHandler.cc b/src/UTMetadataPostDownloadHandler.cc
index 13623fc1..0557a1b1 100644
--- a/src/UTMetadataPostDownloadHandler.cc
+++ b/src/UTMetadataPostDownloadHandler.cc
@@ -58,7 +58,7 @@ bool UTMetadataPostDownloadHandler::Criteria::match
 {
   const SharedHandle<DownloadContext>& dctx =
     requestGroup->getDownloadContext();
-  if(dctx->hasAttribute(bittorrent::BITTORRENT)) {
+  if(dctx->hasAttribute(CTX_ATTR_BT)) {
     SharedHandle<TorrentAttribute> attrs = bittorrent::getTorrentAttrs(dctx);
     if(attrs->metadata.empty()) {
       return true;
diff --git a/src/bittorrent_helper.cc b/src/bittorrent_helper.cc
index ea7f1c5b..e47e4143 100644
--- a/src/bittorrent_helper.cc
+++ b/src/bittorrent_helper.cc
@@ -107,8 +107,6 @@ const std::string C_CREATED_BY("created by");
 const std::string DEFAULT_PEER_ID_PREFIX("aria2-");
 } // namespace
 
-const std::string BITTORRENT("bittorrent");
-
 const std::string MULTI("multi");
 
 const std::string SINGLE("single");
@@ -515,7 +513,7 @@ void processRootDictionary
     torrent->createdBy = util::encodeNonUtf8(createdBy->s());
   }
 
-  ctx->setAttribute(BITTORRENT, torrent);
+  ctx->setAttribute(CTX_ATTR_BT, torrent);
 }
 } // namespace
 
@@ -626,7 +624,7 @@ void loadFromMemory(const SharedHandle<ValueBase>& torrent,
 SharedHandle<TorrentAttribute> getTorrentAttrs
 (const SharedHandle<DownloadContext>& dctx)
 {
-  return static_pointer_cast<TorrentAttribute>(dctx->getAttribute(BITTORRENT));
+  return static_pointer_cast<TorrentAttribute>(dctx->getAttribute(CTX_ATTR_BT));
 }
 
 const unsigned char*
@@ -943,7 +941,7 @@ void loadMagnet
 (const std::string& magnet, const SharedHandle<DownloadContext>& dctx)
 {
   SharedHandle<TorrentAttribute> attrs = parseMagnet(magnet);
-  dctx->setAttribute(BITTORRENT, attrs);
+  dctx->setAttribute(CTX_ATTR_BT, attrs);
 }
 
 std::string metadata2Torrent
diff --git a/src/bittorrent_helper.h b/src/bittorrent_helper.h
index 5f4f17fe..7690d205 100644
--- a/src/bittorrent_helper.h
+++ b/src/bittorrent_helper.h
@@ -64,9 +64,6 @@ extern const std::string SINGLE;
 
 extern const std::string MULTI;
 
-extern const std::string BITTORRENT;
-
-
 void load(const std::string& torrentFile,
           const SharedHandle<DownloadContext>& ctx,
           const SharedHandle<Option>& option,
diff --git a/test/BtDependencyTest.cc b/test/BtDependencyTest.cc
index aa0f4465..885a719e 100644
--- a/test/BtDependencyTest.cc
+++ b/test/BtDependencyTest.cc
@@ -130,8 +130,7 @@ void BtDependencyTest::testResolve_originalNameNoMatch()
   BtDependency dep(dependant.get(), dependee);
   CPPUNIT_ASSERT(dep.resolve());
 
-  CPPUNIT_ASSERT(!dependant->getDownloadContext()->hasAttribute
-                 (bittorrent::BITTORRENT));
+  CPPUNIT_ASSERT(!dependant->getDownloadContext()->hasAttribute(CTX_ATTR_BT));
 }
 
 void BtDependencyTest::testResolve_singleFileWithoutOriginalName()
@@ -145,8 +144,7 @@ void BtDependencyTest::testResolve_singleFileWithoutOriginalName()
   dependee->getPieceStorage()->markAllPiecesDone();
   BtDependency dep(dependant.get(), dependee);
   CPPUNIT_ASSERT(dep.resolve());
-  CPPUNIT_ASSERT(dependant->getDownloadContext()->hasAttribute
-                 (bittorrent::BITTORRENT));
+  CPPUNIT_ASSERT(dependant->getDownloadContext()->hasAttribute(CTX_ATTR_BT));
 }
 
 void BtDependencyTest::testResolve_multiFile()
@@ -163,8 +161,7 @@ void BtDependencyTest::testResolve_multiFile()
   BtDependency dep(dependant.get(), dependee);
   CPPUNIT_ASSERT(dep.resolve());
 
-  CPPUNIT_ASSERT(dependant->getDownloadContext()->hasAttribute
-                 (bittorrent::BITTORRENT));
+  CPPUNIT_ASSERT(dependant->getDownloadContext()->hasAttribute(CTX_ATTR_BT));
 
   const std::vector<SharedHandle<FileEntry> >& fileEntries =
     dependant->getDownloadContext()->getFileEntries();
@@ -194,7 +191,7 @@ void BtDependencyTest::testResolve_metadata()
   pieceStorage->setDownloadFinished(true);
   dependee->setPieceStorage(pieceStorage);
   SharedHandle<TorrentAttribute> attrs(new TorrentAttribute());
-  dependee->getDownloadContext()->setAttribute(bittorrent::BITTORRENT, attrs);
+  dependee->getDownloadContext()->setAttribute(CTX_ATTR_BT, attrs);
 
   BtDependency dep(dependant.get(), dependee);
   CPPUNIT_ASSERT(dep.resolve());
@@ -217,7 +214,7 @@ void BtDependencyTest::testResolve_loadError()
   CPPUNIT_ASSERT(dep.resolve());
     
   CPPUNIT_ASSERT
-    (!dependant->getDownloadContext()->hasAttribute(bittorrent::BITTORRENT));
+    (!dependant->getDownloadContext()->hasAttribute(CTX_ATTR_BT));
   CPPUNIT_ASSERT_EQUAL(std::string("/tmp/outfile.path"),
                        dependant->getFirstFilePath());
 }
@@ -231,7 +228,7 @@ void BtDependencyTest::testResolve_dependeeFailure()
   CPPUNIT_ASSERT(dep.resolve());
   
   CPPUNIT_ASSERT
-    (!dependant->getDownloadContext()->hasAttribute(bittorrent::BITTORRENT));
+    (!dependant->getDownloadContext()->hasAttribute(CTX_ATTR_BT));
   CPPUNIT_ASSERT_EQUAL(std::string("/tmp/outfile.path"),
                        dependant->getFirstFilePath());
 }
diff --git a/test/BtRegistryTest.cc b/test/BtRegistryTest.cc
index 3af3bd13..71b408ac 100644
--- a/test/BtRegistryTest.cc
+++ b/test/BtRegistryTest.cc
@@ -69,10 +69,8 @@ void BtRegistryTest::testGetDownloadContext_infoHash()
   attrs1->infoHash = "hash1";
   SharedHandle<TorrentAttribute> attrs2(new TorrentAttribute());
   attrs2->infoHash = "hash2";
-  btRegistry.getDownloadContext(1)->setAttribute
-    (bittorrent::BITTORRENT, attrs1);
-  btRegistry.getDownloadContext(2)->setAttribute
-    (bittorrent::BITTORRENT, attrs2);
+  btRegistry.getDownloadContext(1)->setAttribute(CTX_ATTR_BT, attrs1);
+  btRegistry.getDownloadContext(2)->setAttribute(CTX_ATTR_BT, attrs2);
 
   CPPUNIT_ASSERT(btRegistry.getDownloadContext("hash1"));
   CPPUNIT_ASSERT(btRegistry.getDownloadContext("hash1").get() ==
diff --git a/test/DefaultBtAnnounceTest.cc b/test/DefaultBtAnnounceTest.cc
index 7f369e8b..06abf95e 100644
--- a/test/DefaultBtAnnounceTest.cc
+++ b/test/DefaultBtAnnounceTest.cc
@@ -59,7 +59,7 @@ public:
     dctx_.reset(new DownloadContext(pieceLength, totalLength));
     SharedHandle<TorrentAttribute> torrentAttrs(new TorrentAttribute());
     torrentAttrs->infoHash = std::string(vbegin(infoHash), vend(infoHash));
-    dctx_->setAttribute(bittorrent::BITTORRENT, torrentAttrs);
+    dctx_->setAttribute(CTX_ATTR_BT, torrentAttrs);
     bittorrent::setStaticPeerId(peerId);
 
     pieceStorage_.reset(new MockPieceStorage());
diff --git a/test/DefaultBtProgressInfoFileTest.cc b/test/DefaultBtProgressInfoFileTest.cc
index 6c87aa05..9d9b8afd 100644
--- a/test/DefaultBtProgressInfoFileTest.cc
+++ b/test/DefaultBtProgressInfoFileTest.cc
@@ -72,7 +72,7 @@ public:
     dctx_.reset(new DownloadContext());
     SharedHandle<TorrentAttribute> torrentAttrs(new TorrentAttribute());
     torrentAttrs->infoHash = std::string(vbegin(infoHash), vend(infoHash));
-    dctx_->setAttribute(bittorrent::BITTORRENT, torrentAttrs);
+    dctx_->setAttribute(CTX_ATTR_BT, torrentAttrs);
     const SharedHandle<FileEntry> fileEntries[] = {
       SharedHandle<FileEntry>(new FileEntry("/path/to/file",totalLength,0))
     };
diff --git a/test/HandshakeExtensionMessageTest.cc b/test/HandshakeExtensionMessageTest.cc
index 567c23a2..4c17038a 100644
--- a/test/HandshakeExtensionMessageTest.cc
+++ b/test/HandshakeExtensionMessageTest.cc
@@ -97,7 +97,7 @@ void HandshakeExtensionMessageTest::testDoReceivedAction()
   rg.setDownloadContext(dctx);
 
   SharedHandle<TorrentAttribute> attrs(new TorrentAttribute());
-  dctx->setAttribute(bittorrent::BITTORRENT, attrs);
+  dctx->setAttribute(CTX_ATTR_BT, attrs);
   dctx->markTotalLengthIsUnknown();
 
   SharedHandle<Peer> peer(new Peer("192.168.0.1", 0));
diff --git a/test/MSEHandshakeTest.cc b/test/MSEHandshakeTest.cc
index 2a29a7c3..8d11a7f1 100644
--- a/test/MSEHandshakeTest.cc
+++ b/test/MSEHandshakeTest.cc
@@ -35,7 +35,7 @@ public:
     memset(infoHash, 0, sizeof(infoHash));
     SharedHandle<TorrentAttribute> torrentAttrs(new TorrentAttribute());
     torrentAttrs->infoHash = std::string(vbegin(infoHash), vend(infoHash));
-    dctx_->setAttribute(bittorrent::BITTORRENT, torrentAttrs);
+    dctx_->setAttribute(CTX_ATTR_BT, torrentAttrs);
   }
 
   void testHandshake();
diff --git a/test/UTMetadataDataExtensionMessageTest.cc b/test/UTMetadataDataExtensionMessageTest.cc
index a3e929ad..7599231d 100644
--- a/test/UTMetadataDataExtensionMessageTest.cc
+++ b/test/UTMetadataDataExtensionMessageTest.cc
@@ -84,7 +84,7 @@ void UTMetadataDataExtensionMessageTest::testDoReceivedAction()
                          MessageDigest::sha1(),
                          metadata.data(), metadata.size());
   attrs->infoHash = std::string(&infoHash[0], &infoHash[20]);
-  dctx->setAttribute(bittorrent::BITTORRENT, attrs);
+  dctx->setAttribute(CTX_ATTR_BT, attrs);
 
   UTMetadataDataExtensionMessage m(1);
   m.setPieceStorage(pieceStorage);
diff --git a/test/UTMetadataPostDownloadHandlerTest.cc b/test/UTMetadataPostDownloadHandlerTest.cc
index b3ae7166..16431f68 100644
--- a/test/UTMetadataPostDownloadHandlerTest.cc
+++ b/test/UTMetadataPostDownloadHandlerTest.cc
@@ -53,7 +53,7 @@ void UTMetadataPostDownloadHandlerTest::testCanHandle()
   CPPUNIT_ASSERT(!handler.canHandle(requestGroup_.get()));
 
   SharedHandle<TorrentAttribute> attrs(new TorrentAttribute());
-  dctx_->setAttribute(bittorrent::BITTORRENT, attrs);
+  dctx_->setAttribute(CTX_ATTR_BT, attrs);
 
   CPPUNIT_ASSERT(handler.canHandle(requestGroup_.get()));
 
@@ -84,7 +84,7 @@ void UTMetadataPostDownloadHandlerTest::testGetNextRequestGroups()
   announceTier.push_back("http://tracker");
   announceList.push_back(announceTier);
   attrs->announceList = announceList;
-  dctx_->setAttribute(bittorrent::BITTORRENT, attrs);
+  dctx_->setAttribute(CTX_ATTR_BT, attrs);
   requestGroup_->setDiskWriterFactory
     (SharedHandle<DiskWriterFactory>(new ByteArrayDiskWriterFactory()));
   requestGroup_->initPieceStorage();
diff --git a/test/UTMetadataRequestExtensionMessageTest.cc b/test/UTMetadataRequestExtensionMessageTest.cc
index e22ae2af..427bce5a 100644
--- a/test/UTMetadataRequestExtensionMessageTest.cc
+++ b/test/UTMetadataRequestExtensionMessageTest.cc
@@ -41,7 +41,7 @@ public:
     dispatcher_.reset(new MockBtMessageDispatcher());
     dctx_.reset(new DownloadContext());
     SharedHandle<TorrentAttribute> attrs(new TorrentAttribute());
-    dctx_->setAttribute(bittorrent::BITTORRENT, attrs);
+    dctx_->setAttribute(CTX_ATTR_BT, attrs);
     peer_.reset(new Peer("host", 6880));
     peer_->allocateSessionResource(0, 0);
     peer_->setExtension("ut_metadata", 1);