diff --git a/src/itemdef.cpp b/src/itemdef.cpp
index a13b3f7d..8e049282 100644
--- a/src/itemdef.cpp
+++ b/src/itemdef.cpp
@@ -270,17 +270,16 @@ public:
 		// Convert name according to possible alias
 		std::string name = getAlias(name_);
 		// Get the definition
-		std::map<std::string, ItemDefinition*>::const_iterator i;
-		i = m_item_definitions.find(name);
-		if(i == m_item_definitions.end())
+		auto i = m_item_definitions.find(name);
+		if (i == m_item_definitions.cend())
 			i = m_item_definitions.find("unknown");
-		assert(i != m_item_definitions.end());
+		assert(i != m_item_definitions.cend());
 		return *(i->second);
 	}
 	virtual const std::string &getAlias(const std::string &name) const
 	{
-		StringMap::const_iterator it = m_aliases.find(name);
-		if (it != m_aliases.end())
+		auto it = m_aliases.find(name);
+		if (it != m_aliases.cend())
 			return it->second;
 		return name;
 	}
@@ -300,8 +299,7 @@ public:
 		// Convert name according to possible alias
 		std::string name = getAlias(name_);
 		// Get the definition
-		std::map<std::string, ItemDefinition*>::const_iterator i;
-		return m_item_definitions.find(name) != m_item_definitions.end();
+		return m_item_definitions.find(name) != m_item_definitions.cend();
 	}
 #ifndef SERVER
 public:
@@ -443,11 +441,9 @@ public:
 	}
 	void clear()
 	{
-		for(std::map<std::string, ItemDefinition*>::const_iterator
-				i = m_item_definitions.begin();
-				i != m_item_definitions.end(); ++i)
+		for (auto &i : m_item_definitions)
 		{
-			delete i->second;
+			delete i.second;
 		}
 		m_item_definitions.clear();
 		m_aliases.clear();
@@ -520,10 +516,8 @@ public:
 		u16 count = m_item_definitions.size();
 		writeU16(os, count);
 
-		for (std::map<std::string, ItemDefinition *>::const_iterator
-				it = m_item_definitions.begin();
-				it != m_item_definitions.end(); ++it) {
-			ItemDefinition *def = it->second;
+		for (const auto &it : m_item_definitions) {
+			ItemDefinition *def = it.second;
 			// Serialize ItemDefinition and write wrapped in a string
 			std::ostringstream tmp_os(std::ios::binary);
 			def->serialize(tmp_os, protocol_version);
@@ -532,11 +526,9 @@ public:
 
 		writeU16(os, m_aliases.size());
 
-		for (StringMap::const_iterator
-				it = m_aliases.begin();
-				it != m_aliases.end(); ++it) {
-			os << serializeString(it->first);
-			os << serializeString(it->second);
+		for (const auto &it : m_aliases) {
+			os << serializeString(it.first);
+			os << serializeString(it.second);
 		}
 	}
 	void deSerialize(std::istream &is)
diff --git a/src/script/lua_api/l_item.cpp b/src/script/lua_api/l_item.cpp
index 9f12d3ac..0a403acb 100644
--- a/src/script/lua_api/l_item.cpp
+++ b/src/script/lua_api/l_item.cpp
@@ -609,10 +609,21 @@ int ModApiItemMod::l_get_content_id(lua_State *L)
 	NO_MAP_LOCK_REQUIRED;
 	std::string name = luaL_checkstring(L, 1);
 
+	const IItemDefManager *idef = getGameDef(L)->getItemDefManager();
 	const NodeDefManager *ndef = getGameDef(L)->getNodeDefManager();
+
+	// If this is called at mod load time, NodeDefManager isn't aware of
+	// aliases yet, so we need to handle them manually
+	std::string alias_name = idef->getAlias(name);
+
 	content_t content_id;
-	if (!ndef->getId(name, content_id))
+	if (alias_name != name) {
+		if (!ndef->getId(alias_name, content_id))
+			throw LuaError("Unknown node: " + alias_name +
+					" (from alias " + name + ")");
+	} else if (!ndef->getId(name, content_id)) {
 		throw LuaError("Unknown node: " + name);
+	}
 
 	lua_pushinteger(L, content_id);
 	return 1; /* number of results */