diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 64c883b7f6..229cedf55c 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -2006,7 +2006,7 @@ void Application::updateAvatars(float deltaTime, glm::vec3 mouseRayOrigin, glm::
     PerformanceWarning warn(showWarnings, "Application::updateAvatars()");
 
     foreach (const SharedNodePointer& node, NodeList::getInstance()->getNodeHash()) {
-        QMutexLocker(&node->getMutex());
+        QMutexLocker locker(&node->getMutex());
         if (node->getLinkedData()) {
             Avatar *avatar = (Avatar *)node->getLinkedData();
             if (!avatar->isInitialized()) {
@@ -3659,7 +3659,7 @@ void Application::renderAvatars(bool forceRenderHead, bool selfAvatarOnly) {
         NodeList* nodeList = NodeList::getInstance();
 
         foreach (const SharedNodePointer& node, nodeList->getNodeHash()) {
-            QMutexLocker(&node->getMutex());
+            QMutexLocker locker(&node->getMutex());
 
             if (node->getLinkedData() != NULL && node->getType() == NODE_TYPE_AGENT) {
                 Avatar *avatar = (Avatar *)node->getLinkedData();
diff --git a/libraries/octree/src/JurisdictionListener.cpp b/libraries/octree/src/JurisdictionListener.cpp
index ae27259f83..d8919ac48e 100644
--- a/libraries/octree/src/JurisdictionListener.cpp
+++ b/libraries/octree/src/JurisdictionListener.cpp
@@ -20,12 +20,9 @@ JurisdictionListener::JurisdictionListener(NODE_TYPE type, PacketSenderNotify* n
 {
     _nodeType = type;
     ReceivedPacketProcessor::_dontSleep = true; // we handle sleeping so this class doesn't need to
-    NodeList* nodeList = NodeList::getInstance();
     
-    connect(nodeList, SIGNAL(nodeKilled(SharedNodePointer)), SLOT(nodeKilled(SharedNodePointer)));
-    
-    //qDebug("JurisdictionListener::JurisdictionListener(NODE_TYPE type=%c)\n", type);
-
+//  connect(nodeList, &NodeList::nodeKilled, this, &JurisdictionListener::nodeKilled);
+//  qDebug("JurisdictionListener::JurisdictionListener(NODE_TYPE type=%c)\n", type);
 }
 
 void JurisdictionListener::nodeKilled(SharedNodePointer node) {
diff --git a/libraries/shared/src/NodeList.cpp b/libraries/shared/src/NodeList.cpp
index 06d2bbe05b..f33137a092 100644
--- a/libraries/shared/src/NodeList.cpp
+++ b/libraries/shared/src/NodeList.cpp
@@ -56,6 +56,7 @@ NodeList* NodeList::getInstance() {
 
 NodeList::NodeList(char newOwnerType, unsigned short int newSocketListenPort) :
     _nodeHash(),
+    _nodeHashMutex(),
     _domainHostname(DEFAULT_DOMAIN_HOSTNAME),
     _domainSockAddr(HifiSockAddr(QHostAddress::Null, DEFAULT_DOMAIN_SERVER_PORT)),
     _nodeSocket(),
@@ -230,7 +231,7 @@ void NodeList::processBulkNodeData(const HifiSockAddr& senderAddress, unsigned c
 }
 
 int NodeList::updateNodeWithData(Node *node, const HifiSockAddr& senderSockAddr, unsigned char *packetData, int dataBytes) {
-    QMutexLocker(&node->getMutex());
+    QMutexLocker locker(&node->getMutex());
 
     node->setLastHeardMicrostamp(usecTimestampNow());
 
@@ -266,19 +267,25 @@ SharedNodePointer NodeList::nodeWithAddress(const HifiSockAddr &senderSockAddr)
 }
 
 SharedNodePointer NodeList::nodeWithUUID(const QUuid& nodeUUID) {
+    QMutexLocker locker(&_nodeHashMutex);
     return _nodeHash.value(nodeUUID);
 }
 
+NodeHash NodeList::getNodeHash() {
+    QMutexLocker locker(&_nodeHashMutex);
+    return NodeHash(_nodeHash);
+}
+
 void NodeList::clear() {
     qDebug() << "Clearing the NodeList. Deleting all nodes in list.";
+    
+    QMutexLocker locker(&_nodeHashMutex);
 
     NodeHash::iterator nodeItem = _nodeHash.begin();
 
     // iterate the nodes in the list
     while (nodeItem != _nodeHash.end()) {
-        NodeHash::iterator previousNodeItem = nodeItem;
-        ++nodeItem;
-        killNodeAtHashIterator(previousNodeItem);
+        nodeItem = killNodeAtHashIterator(nodeItem);
     }
 }
 
@@ -438,16 +445,18 @@ void NodeList::processSTUNResponse(unsigned char* packetData, size_t dataBytes)
 }
 
 void NodeList::killNodeWithUUID(const QUuid& nodeUUID) {
+    QMutexLocker locker(&_nodeHashMutex);
+    
     NodeHash::iterator nodeItemToKill = _nodeHash.find(nodeUUID);
     if (nodeItemToKill != _nodeHash.end()) {
         killNodeAtHashIterator(nodeItemToKill);
     }
 }
 
-void NodeList::killNodeAtHashIterator(NodeHash::iterator& nodeItemToKill) {
+NodeHash::iterator NodeList::killNodeAtHashIterator(NodeHash::iterator& nodeItemToKill) {
     qDebug() << "Killed" << *nodeItemToKill.value();
     emit nodeKilled(nodeItemToKill.value());
-    _nodeHash.erase(nodeItemToKill);
+    return _nodeHash.erase(nodeItemToKill);
 }
 
 void NodeList::sendKillNode(const char* nodeTypes, int numNodeTypes) {
@@ -674,6 +683,8 @@ void NodeList::pingPublicAndLocalSocketsForInactiveNode(Node* node) {
 
 SharedNodePointer NodeList::addOrUpdateNode(const QUuid& uuid, char nodeType,
                                 const HifiSockAddr& publicSocket, const HifiSockAddr& localSocket) {
+    _nodeHashMutex.lock();
+    
     SharedNodePointer matchingNode = _nodeHash.value(uuid);
     
     if (!matchingNode) {
@@ -683,13 +694,17 @@ SharedNodePointer NodeList::addOrUpdateNode(const QUuid& uuid, char nodeType,
 
         _nodeHash.insert(newNode->getUUID(), newNodeSharedPointer);
 
+        _nodeHashMutex.unlock();
+        
         qDebug() << "Added" << *newNode;
 
         emit nodeAdded(newNodeSharedPointer);
 
         return newNodeSharedPointer;
     } else {
-        QMutexLocker(&matchingNode->getMutex());
+        _nodeHashMutex.unlock();
+        
+        QMutexLocker locker(&matchingNode->getMutex());
 
         if (matchingNode->getType() == NODE_TYPE_AUDIO_MIXER ||
             matchingNode->getType() == NODE_TYPE_VOXEL_SERVER ||
@@ -781,24 +796,27 @@ SharedNodePointer NodeList::soloNodeOfType(char nodeType) {
 
 void NodeList::removeSilentNodes() {
 
+    _nodeHashMutex.lock();
+    
     NodeHash::iterator nodeItem = _nodeHash.begin();
 
     while (nodeItem != _nodeHash.end()) {
         SharedNodePointer node = nodeItem.value();
 
-        QMutexLocker(&node->getMutex());
+        node->getMutex().lock();
 
         if ((usecTimestampNow() - node->getLastHeardMicrostamp()) > NODE_SILENCE_THRESHOLD_USECS) {
             // call our private method to kill this node (removes it and emits the right signal)
-            NodeHash::iterator previousNodeItem = nodeItem;
-            ++nodeItem;
-
-            killNodeAtHashIterator(previousNodeItem);
+            nodeItem = killNodeAtHashIterator(nodeItem);
         } else {
             // we didn't kill this node, push the iterator forwards
             ++nodeItem;
         }
+        
+        node->getMutex().unlock();
     }
+    
+    _nodeHashMutex.unlock();
 }
 
 const QString QSETTINGS_GROUP_NAME = "NodeList";
diff --git a/libraries/shared/src/NodeList.h b/libraries/shared/src/NodeList.h
index 391e329200..b5e27564b1 100644
--- a/libraries/shared/src/NodeList.h
+++ b/libraries/shared/src/NodeList.h
@@ -21,6 +21,7 @@
 #include <unistd.h> // not on windows, not needed for mac or windows
 #endif
 
+#include <QtCore/QMutex>
 #include <QtCore/QSettings>
 #include <QtCore/QSharedPointer>
 #include <QtNetwork/QHostAddress>
@@ -81,7 +82,7 @@ public:
 
     void(*linkedDataCreateCallback)(Node *);
 
-    const NodeHash& getNodeHash() { return _nodeHash; }
+    NodeHash getNodeHash();
     int size() const { return _nodeHash.size(); }
 
     int getNumNoReplyDomainCheckIns() const { return _numNoReplyDomainCheckIns; }
@@ -140,9 +141,10 @@ private:
     void processSTUNResponse(unsigned char* packetData, size_t dataBytes);
 
     void processKillNode(unsigned char* packetData, size_t dataBytes);
-    void killNodeAtHashIterator(NodeHash::iterator& nodeItemToKill);
+    NodeHash::iterator killNodeAtHashIterator(NodeHash::iterator& nodeItemToKill);
 
     NodeHash _nodeHash;
+    QMutex _nodeHashMutex;
     QString _domainHostname;
     HifiSockAddr _domainSockAddr;
     QUdpSocket _nodeSocket;