diff --git a/src/content_cao.cpp b/src/content_cao.cpp
index da68004ce..0531fe489 100644
--- a/src/content_cao.cpp
+++ b/src/content_cao.cpp
@@ -183,12 +183,16 @@ public:
 		{return &m_selection_box;}
 	v3f getPosition()
 		{return m_position;}
+	
+	std::string infoText()
+		{return m_infotext;}
 
 private:
 	core::aabbox3d<f32> m_selection_box;
 	scene::IMeshSceneNode *m_node;
 	v3f m_position;
 	std::string m_inventorystring;
+	std::string m_infotext;
 };
 
 /*
@@ -530,7 +534,10 @@ ItemCAO::ItemCAO(IGameDef *gamedef, ClientEnvironment *env):
 	m_node(NULL),
 	m_position(v3f(0,10*BS,0))
 {
-	ClientActiveObject::registerType(getType(), create);
+	if(!gamedef && !env)
+	{
+		ClientActiveObject::registerType(getType(), create);
+	}
 }
 
 ItemCAO::~ItemCAO()
@@ -694,6 +701,23 @@ void ItemCAO::initialize(const std::string &data)
 	}
 	
 	updateNodePos();
+	
+	/*
+		Set infotext to item name if item cannot be deserialized
+	*/
+	try{
+		InventoryItem *item = NULL;
+		item = InventoryItem::deSerialize(m_inventorystring, m_gamedef);
+		if(item){
+			if(!item->isKnown())
+				m_infotext = "Unknown item: '" + m_inventorystring + "'";
+		}
+		delete item;
+	}
+	catch(SerializationError &e)
+	{
+		m_infotext = "Unknown item: '" + m_inventorystring + "'";
+	}
 }
 
 /*
diff --git a/src/inventory.cpp b/src/inventory.cpp
index 1e1e27c82..a913430e6 100644
--- a/src/inventory.cpp
+++ b/src/inventory.cpp
@@ -343,6 +343,13 @@ video::ITexture * ToolItem::getImageRaw() const
 }
 #endif
 
+bool ToolItem::isKnown() const
+{
+	IToolDefManager *tdef = m_gamedef->tdef();
+	const ToolDefinition *def = tdef->getToolDefinition(m_toolname);
+	return (def != NULL);
+}
+
 /*
 	CraftItem
 */
@@ -357,6 +364,13 @@ video::ITexture * CraftItem::getImage() const
 }
 #endif
 
+bool CraftItem::isKnown() const
+{
+	ICraftItemDefManager *cidef = m_gamedef->cidef();
+	const CraftItemDefinition *def = cidef->getCraftItemDefinition(m_subname);
+	return (def != NULL);
+}
+
 u16 CraftItem::getStackMax() const
 {
 	ICraftItemDefManager *cidef = m_gamedef->cidef();
diff --git a/src/inventory.h b/src/inventory.h
index 93a29764c..3f3c5435b 100644
--- a/src/inventory.h
+++ b/src/inventory.h
@@ -64,6 +64,9 @@ public:
 	virtual std::string getText() { return ""; }
 	// Returns the string used for inventory
 	virtual std::string getItemString();
+	
+	// Shall return false if item is not known and cannot be used
+	virtual bool isKnown() const { return true; }
 
 	/*
 		Quantity methods
@@ -269,6 +272,8 @@ public:
 		return os.str();
 	}
 
+	virtual bool isKnown() const;
+
 	virtual bool addableTo(const InventoryItem *other) const
 	{
 		if(std::string(other->getName()) != "CraftItem")
@@ -366,6 +371,8 @@ public:
 	{
 		return "";
 	}
+	
+	virtual bool isKnown() const;
 
 	virtual bool isSubsetOf(const InventoryItem *other) const
 	{