diff --git a/common/protocolmanager.cpp b/common/protocolmanager.cpp
index 9ed67f5..e91f270 100644
--- a/common/protocolmanager.cpp
+++ b/common/protocolmanager.cpp
@@ -164,6 +164,11 @@ void ProtocolManager::populateNeighbourProtocols()
     }
 }
 
+bool ProtocolManager::isRegisteredProtocol(int protoNumber)
+{
+    return factory.contains(protoNumber);
+}
+
 AbstractProtocol* ProtocolManager::createProtocol(int protoNumber,
     StreamBase *stream, AbstractProtocol *parent)
 {
diff --git a/common/protocolmanager.h b/common/protocolmanager.h
index 77ea81c..07b0604 100644
--- a/common/protocolmanager.h
+++ b/common/protocolmanager.h
@@ -42,6 +42,7 @@ public:
 
     void registerProtocol(int protoNumber, void *protoInstanceCreator);
 
+    bool isRegisteredProtocol(int protoNumber);
     AbstractProtocol* createProtocol(int protoNumber, StreamBase *stream,
         AbstractProtocol *parent = 0);
     AbstractProtocol* createProtocol(QString protoName, StreamBase *stream,
diff --git a/common/streambase.cpp b/common/streambase.cpp
index 53addbe..b9dea25 100644
--- a/common/streambase.cpp
+++ b/common/streambase.cpp
@@ -89,8 +89,14 @@ void StreamBase::protoDataCopyFrom(const OstProto::Stream &stream)
     iter = createProtocolListIterator();
     for (int i=0; i < stream.protocol_size(); i++)
     {
-        proto = OstProtocolManager->createProtocol(
-            stream.protocol(i).protocol_id().id(), this);
+        int protoId = stream.protocol(i).protocol_id().id();
+
+        if (!OstProtocolManager->isRegisteredProtocol(protoId))
+        {
+            qWarning("Skipping unregistered protocol %d", protoId);
+            continue;
+        }
+        proto = OstProtocolManager->createProtocol(protoId, this);
         proto->protoDataCopyFrom(stream.protocol(i));
         iter->insert(proto);
     }