diff --git a/builtin/game/features.lua b/builtin/game/features.lua
index 874d3e885..a27160961 100644
--- a/builtin/game/features.lua
+++ b/builtin/game/features.lua
@@ -39,6 +39,7 @@ core.features = {
 	dynamic_add_media_filepath = true,
 	lsystem_decoration_type = true,
 	item_meta_range = true,
+	have_guids = true,
 }
 
 function core.has_feature(arg)
diff --git a/doc/lua_api.md b/doc/lua_api.md
index cca231c73..a6139d897 100644
--- a/doc/lua_api.md
+++ b/doc/lua_api.md
@@ -5432,6 +5432,8 @@ Utilities
       lsystem_decoration_type = true,
       -- Overrideable pointing range using the itemstack meta key `"range"` (5.9.0)
       item_meta_range = true,
+      -- objects have get_guid method and lua entities alse set_guid method (5.9.0)
+      have_guids = true,
   }
   ```
 
@@ -7283,6 +7285,8 @@ Global tables
       as they are only read when spawning.
 * `minetest.object_refs`
     * Map of object references, indexed by active object id
+* `minetest.objects_by_guid`
+    * Map of object references, indexed by active object GUID
 * `minetest.luaentities`
     * Map of Lua entities, indexed by active object id
 * `minetest.registered_abms`
@@ -7934,6 +7938,9 @@ child will follow movement and rotation of that bone.
           -- Default: false
       }
       ```
+* `get_guid()`: returns a global unique identifier (a string)
+    * For players a global unique identiticator is a player name.
+    * For non-player objects, it is unique generated string.
 
 #### Lua entity only (no-op for other objects)
 
@@ -7941,6 +7948,10 @@ child will follow movement and rotation of that bone.
     * The object is removed after returning from Lua. However the `ObjectRef`
       itself instantly becomes unusable with all further method calls having
       no effect and returning `nil`.
+* `set_guid(guid)`: 
+    * Set a global unique identifier string of entity.
+    * Is valid to be called only in `on_activate` callback.
+    * Should be used ONLY for restoring saved guid from staticdata!!!
 * `set_velocity(vel)`
     * Sets the velocity
     * `vel` is a vector, e.g. `{x=0.0, y=2.3, z=1.0}`
diff --git a/doc/world_format.md b/doc/world_format.md
index b5a2a3cfa..be7571cc9 100644
--- a/doc/world_format.md
+++ b/doc/world_format.md
@@ -582,6 +582,9 @@ Since protocol version 37:
 * `u8` `version2` (=1)
 * `s32` pitch * 1000
 * `s32` roll * 1000
+* if version2 >= 2:
+  * u32 len
+  * u8[len] guid
 
 # Itemstring Format
 
diff --git a/games/devtest/mods/unittests/entity.lua b/games/devtest/mods/unittests/entity.lua
index 565dd6adf..394aae0e4 100644
--- a/games/devtest/mods/unittests/entity.lua
+++ b/games/devtest/mods/unittests/entity.lua
@@ -52,6 +52,22 @@ core.register_entity("unittests:callbacks", {
 	end,
 })
 
+core.register_entity("unittests:guid", {
+	initial_properties = {
+		static_save = false,
+	},
+	on_activate = function(self, staticdata, dtime_s)
+    self.object:set_guid("@UNITTEST")
+		insert_log("on_activate(%d)", #staticdata)
+	end,
+	on_deactivate = function(self, removal)
+		insert_log("on_deactivate(%s)", tostring(removal))
+	end,
+	get_staticdata = function(self)
+		assert(false)
+	end,
+})
+
 --
 
 local function check_log(expect)
@@ -130,3 +146,26 @@ local function test_entity_attach(player, pos)
 	obj:remove()
 end
 unittests.register("test_entity_attach", test_entity_attach, {player=true, map=true})
+
+local function test_entity_guid(_, pos)
+	log = {}
+
+	local obj = core.add_entity(pos, "unittests:callbacks")
+	check_log({"on_activate(0)"})
+
+	assert(obj:get_guid()~="")
+
+	obj:remove()
+	check_log({"on_deactivate(true)"})
+
+	assert(core.objects_by_guid["@UNITTEST"]==nil)
+	obj = core.add_entity(pos, "unittests:guid")
+	check_log({"on_activate(0)"})
+
+	assert(obj:get_guid()=="@UNITTEST")
+	assert(core.objects_by_guid["@UNITTEST"]~=nil)
+
+	obj:remove()
+end
+unittests.register("test_entity_guid", test_entity_guid, {map=true})
+
diff --git a/games/devtest/mods/unittests/player.lua b/games/devtest/mods/unittests/player.lua
index 70b3b6cae..d496f77ef 100644
--- a/games/devtest/mods/unittests/player.lua
+++ b/games/devtest/mods/unittests/player.lua
@@ -84,3 +84,10 @@ local function run_player_add_pos_tests(player)
 end
 unittests.register("test_player_add_pos", run_player_add_pos_tests, {player=true})
 
+--
+-- Player get uuid
+--
+local function test_player_guid_tests(player)
+	assert(player:get_guid()==player:get_player_name())
+end
+unittests.register("test_player_guid", test_player_guid_tests, {player=true})
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index bf849493a..fcc2aa697 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -381,6 +381,7 @@ set(common_SRCS
 	face_position_cache.cpp
 	filesys.cpp
 	gettext.cpp
+	guid.cpp
 	httpfetch.cpp
 	hud.cpp
 	inventory.cpp
diff --git a/src/guid.cpp b/src/guid.cpp
new file mode 100644
index 000000000..1709adb58
--- /dev/null
+++ b/src/guid.cpp
@@ -0,0 +1,50 @@
+/*
+Minetest
+Copyright (C) 2021, DS
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser 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.
+*/
+
+#include "guid.h"
+#include <sstream>
+
+#include "serverenvironment.h"
+#include "util/base64.h"
+
+GUIdGenerator::GUIdGenerator() :
+	m_uniform(0, UINT64_MAX)
+{
+	m_rand_usable = m_rand.entropy() > 0.01;
+}
+
+GUId GUIdGenerator::next(const std::string &prefix)
+{
+	std::stringstream s_guid;
+
+	u64 a[2];
+	if (m_rand_usable) {
+		a[0] = m_uniform(m_rand);
+		a[1] = m_uniform(m_rand);
+	}
+	else {
+		a[0] = (static_cast<u64>(m_env->getGameTime()) << 32) + m_next;
+		a[1] = m_uniform(m_rand);
+		m_next++;
+	}
+	s_guid << prefix << base64_encode(std::string_view(reinterpret_cast<char *>(a), 16));
+
+	return s_guid.str();
+}
+
diff --git a/src/guid.h b/src/guid.h
new file mode 100644
index 000000000..e2698f0d5
--- /dev/null
+++ b/src/guid.h
@@ -0,0 +1,68 @@
+/*
+Minetest
+Copyright (C) 2021, DS
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser 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.
+*/
+
+#pragma once
+
+#include "irrlichttypes.h"
+#include "util/basic_macros.h"
+#include <random>
+#include <string>
+
+class ServerEnvironment;
+
+/**
+ * A global unique identifier.
+ * It is global because it stays valid in a world forever.
+ * It is unique because there are no collisions.
+ */
+typedef std::string GUId;
+
+/**
+ * Generates infinitely many guids.
+ */
+class GUIdGenerator {
+public:
+	/**
+	 * Creates a new uninitialized generator.
+	 * @param env ServerEnvironment where generator is running
+	 * @param prefix Prefix of generated GUId
+	 * @param next next value getted from loadMeta
+	 */
+	GUIdGenerator();
+
+	~GUIdGenerator() = default;
+	DISABLE_CLASS_COPY(GUIdGenerator)
+
+	/**
+	 * Generates the next guid, which it will never return again.
+	 * @return the new guid, or "" if the generator is not yet initialized
+	 */
+	GUId next(const std::string &prefix);
+
+private:
+	void setServerEnvironment(ServerEnvironment *env) { m_env = env; }
+  
+	ServerEnvironment *m_env;
+	std::random_device m_rand;
+	std::uniform_int_distribution<u64> m_uniform;
+	bool m_rand_usable;
+	u32 m_next;
+  
+	friend class ServerEnvironment;
+};
diff --git a/src/script/cpp_api/s_base.cpp b/src/script/cpp_api/s_base.cpp
index 7731de7a7..1164e2588 100644
--- a/src/script/cpp_api/s_base.cpp
+++ b/src/script/cpp_api/s_base.cpp
@@ -433,11 +433,12 @@ void ScriptApiBase::setOriginFromTableRaw(int index, const char *fxn)
 /*
  * How ObjectRefs are handled in Lua:
  * When an active object is created, an ObjectRef is created on the Lua side
- * and stored in core.object_refs[id].
+ * and stored in core.object_refs[id] and in core.objects_by_guids[[GUID].
  * Methods that require an ObjectRef to a certain object retrieve it from that
  * table instead of creating their own.(*)
  * When an active object is removed, the existing ObjectRef is invalidated
- * using ::set_null() and removed from the core.object_refs table.
+ * using ::set_null() and removed from the core.object_refs and
+ * core.object_by_guids tables.
  * (*) An exception to this are NULL ObjectRefs and anonymous ObjectRefs
  *     for objects without ID.
  *     It's unclear what the latter are needed for and their use is problematic
@@ -465,6 +466,27 @@ void ScriptApiBase::addObjectReference(ServerActiveObject *cobj)
 	lua_settable(L, objectstable);
 }
 
+void ScriptApiBase::addObjectByGuid(ServerActiveObject *cobj)
+{
+	SCRIPTAPI_PRECHECKHEADER
+	assert(getType() == ScriptingType::Server);
+
+	// Create object on stack
+	ObjectRef::create(L, cobj); // Puts ObjectRef (as userdata) on stack
+	int object = lua_gettop(L);
+
+	// Get core.objects_by_guid table
+	lua_getglobal(L, "core");
+	lua_getfield(L, -1, "objects_by_guid");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	int objectstable = lua_gettop(L);
+
+	// objects_by_guid[GUID] = object
+	lua_pushstring(L, cobj->getGuid().c_str()); // Push GUID
+	lua_pushvalue(L, object); // Copy object to top of stack
+	lua_settable(L, objectstable);
+}
+
 void ScriptApiBase::removeObjectReference(ServerActiveObject *cobj)
 {
 	SCRIPTAPI_PRECHECKHEADER
@@ -472,6 +494,7 @@ void ScriptApiBase::removeObjectReference(ServerActiveObject *cobj)
 
 	// Get core.object_refs table
 	lua_getglobal(L, "core");
+	int core = lua_gettop(L);
 	lua_getfield(L, -1, "object_refs");
 	luaL_checktype(L, -1, LUA_TTABLE);
 	int objectstable = lua_gettop(L);
@@ -484,7 +507,17 @@ void ScriptApiBase::removeObjectReference(ServerActiveObject *cobj)
 	lua_pop(L, 1); // pop object
 
 	// Set object_refs[id] = nil
-	lua_pushnumber(L, cobj->getId()); // Push id
+	lua_pushnumber(L, cobj->getId()); // Push GUID
+	lua_pushnil(L);
+	lua_settable(L, objectstable);
+
+	// Get core.objects_by_guid
+	lua_getfield(L, core, "objects_by_guid");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	objectstable = lua_gettop(L);
+
+	// Set objects_by_guid[GUID] = nil
+	lua_pushstring(L, cobj->getGuid().c_str()); // Push GUID
 	lua_pushnil(L);
 	lua_settable(L, objectstable);
 }
diff --git a/src/script/cpp_api/s_base.h b/src/script/cpp_api/s_base.h
index ac74c2e68..9eab805d0 100644
--- a/src/script/cpp_api/s_base.h
+++ b/src/script/cpp_api/s_base.h
@@ -100,6 +100,7 @@ public:
 
 	/* object */
 	void addObjectReference(ServerActiveObject *cobj);
+	void addObjectByGuid(ServerActiveObject *cobj);
 	void removeObjectReference(ServerActiveObject *cobj);
 
 	ScriptingType getType() { return m_type; }
diff --git a/src/script/lua_api/l_object.cpp b/src/script/lua_api/l_object.cpp
index ad4b7af41..30d5da3cd 100644
--- a/src/script/lua_api/l_object.cpp
+++ b/src/script/lua_api/l_object.cpp
@@ -106,6 +106,21 @@ int ObjectRef::l_remove(lua_State *L)
 	return 0;
 }
 
+// get_guid()
+int ObjectRef::l_get_guid(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	ObjectRef *ref = checkObject<ObjectRef>(L, 1);
+	ServerActiveObject *sao = getobject(ref);
+	if (sao == nullptr)
+		return 0;
+
+	const std::string &guid = sao->getGuid();
+
+	lua_pushstring(L, guid.c_str());
+	return 1;
+}
+
 // get_pos(self)
 int ObjectRef::l_get_pos(lua_State *L)
 {
@@ -1120,6 +1135,25 @@ int ObjectRef::l_set_sprite(lua_State *L)
 	return 0;
 }
 
+// set_guid(self, guid)
+int ObjectRef::l_set_guid(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	ObjectRef *ref = checkObject<ObjectRef>(L, 1);
+	LuaEntitySAO *entitysao = getluaobject(ref);
+	if (entitysao == nullptr)
+		return 0;
+
+	std::string guid = readParam<std::string>(L, 2, "");
+
+	if (!guid.empty())
+		lua_pushboolean(L, entitysao->setGuid(guid));
+	else
+		lua_pushboolean(L, false);
+
+	return 1;
+}
+
 // DEPRECATED
 // get_entity_name(self)
 int ObjectRef::l_get_entity_name(lua_State *L)
@@ -2632,6 +2666,7 @@ const char ObjectRef::className[] = "ObjectRef";
 luaL_Reg ObjectRef::methods[] = {
 	// ServerActiveObject
 	luamethod(ObjectRef, remove),
+	luamethod(ObjectRef, get_guid),
 	luamethod_aliased(ObjectRef, get_pos, getpos),
 	luamethod_aliased(ObjectRef, set_pos, setpos),
 	luamethod(ObjectRef, add_pos),
@@ -2679,6 +2714,7 @@ luaL_Reg ObjectRef::methods[] = {
 	luamethod_aliased(ObjectRef, set_texture_mod, settexturemod),
 	luamethod(ObjectRef, get_texture_mod),
 	luamethod_aliased(ObjectRef, set_sprite, setsprite),
+	luamethod(ObjectRef, set_guid),
 	luamethod(ObjectRef, get_entity_name),
 	luamethod(ObjectRef, get_luaentity),
 
diff --git a/src/script/lua_api/l_object.h b/src/script/lua_api/l_object.h
index 73264db10..ff072040b 100644
--- a/src/script/lua_api/l_object.h
+++ b/src/script/lua_api/l_object.h
@@ -67,6 +67,9 @@ private:
 	// remove(self)
 	static int l_remove(lua_State *L);
 
+	// get_guid()
+	static int l_get_guid(lua_State *L);
+
 	// get_pos(self)
 	static int l_get_pos(lua_State *L);
 
@@ -200,6 +203,9 @@ private:
 
 	// set_sprite(self, start_frame, num_frames, framelength, select_x_by_camera)
 	static int l_set_sprite(lua_State *L);
+	
+	// set_guid(self, guid)
+	static int l_set_guid(lua_State *L);
 
 	// DEPRECATED
 	// get_entity_name(self)
diff --git a/src/script/scripting_server.cpp b/src/script/scripting_server.cpp
index 324850011..933e769d7 100644
--- a/src/script/scripting_server.cpp
+++ b/src/script/scripting_server.cpp
@@ -76,6 +76,9 @@ ServerScripting::ServerScripting(Server* server):
 	lua_newtable(L);
 	lua_setfield(L, -2, "object_refs");
 
+	lua_newtable(L);
+	lua_setfield(L, -2, "objects_by_guid");
+
 	lua_newtable(L);
 	lua_setfield(L, -2, "luaentities");
 
diff --git a/src/server/luaentity_sao.cpp b/src/server/luaentity_sao.cpp
index 963fd63dc..caafe3950 100644
--- a/src/server/luaentity_sao.cpp
+++ b/src/server/luaentity_sao.cpp
@@ -85,6 +85,13 @@ LuaEntitySAO::LuaEntitySAO(ServerEnvironment *env, v3f pos, const std::string &d
 	m_rotation = rotation;
 }
 
+LuaEntitySAO::LuaEntitySAO(ServerEnvironment *env, v3f pos, const std::string &name,
+		const std::string &state) :
+		UnitSAO(env, pos),
+		m_init_name(name), m_init_state(state)
+{
+}
+
 LuaEntitySAO::~LuaEntitySAO()
 {
 	if(m_registered){
@@ -113,6 +120,10 @@ void LuaEntitySAO::addedToEnvironment(u32 dtime_s)
 		// Activate entity, supplying serialized state
 		m_env->getScriptIface()->
 			luaentity_Activate(m_id, m_init_state, dtime_s);
+		// if Activate callback does not set guid, set it. 
+		if (m_guid.empty()) {
+			getGuid();
+		}
 	} else {
 		// It's an unknown object
 		// Use entitystring as infotext for debugging
@@ -428,6 +439,22 @@ u16 LuaEntitySAO::getHP() const
 	return m_hp;
 }
 
+bool LuaEntitySAO::setGuid(std::string &guid)
+{
+	if (m_guid.empty()) {
+		m_guid = guid;
+		return true;
+	}
+	return false;
+}
+GUId LuaEntitySAO::getGuid()
+{
+	if (m_guid.empty()) {
+		m_guid = m_env->getGUIdGenerator().next(std::string("@"));
+	}
+	return m_guid;
+}
+
 void LuaEntitySAO::setVelocity(v3f velocity)
 {
 	m_velocity = velocity;
diff --git a/src/server/luaentity_sao.h b/src/server/luaentity_sao.h
index 2080df9c3..9e5b4c7ee 100644
--- a/src/server/luaentity_sao.h
+++ b/src/server/luaentity_sao.h
@@ -21,6 +21,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #pragma once
 
 #include "unit_sao.h"
+#include "guid.h"
 
 class LuaEntitySAO : public UnitSAO
 {
@@ -30,11 +31,7 @@ public:
 	LuaEntitySAO(ServerEnvironment *env, v3f pos, const std::string &data);
 	// Used by the Lua API
 	LuaEntitySAO(ServerEnvironment *env, v3f pos, const std::string &name,
-			const std::string &state) :
-			UnitSAO(env, pos),
-			m_init_name(name), m_init_state(state)
-	{
-	}
+			const std::string &state);
 	~LuaEntitySAO();
 
 	ActiveObjectType getType() const { return ACTIVEOBJECT_TYPE_LUAENTITY; }
@@ -62,6 +59,8 @@ public:
 
 	void setHP(s32 hp, const PlayerHPChangeReason &reason);
 	u16 getHP() const;
+	bool setGuid(std::string &guid);
+	GUId getGuid() override;
 
 	/* LuaEntitySAO-specific */
 	void setVelocity(v3f velocity);
@@ -95,6 +94,8 @@ private:
 	std::string m_init_state;
 	bool m_registered = false;
 
+	GUId m_guid;
+
 	v3f m_velocity;
 	v3f m_acceleration;
 
diff --git a/src/server/player_sao.cpp b/src/server/player_sao.cpp
index 0806ffd73..86b73ae27 100644
--- a/src/server/player_sao.cpp
+++ b/src/server/player_sao.cpp
@@ -30,6 +30,7 @@ PlayerSAO::PlayerSAO(ServerEnvironment *env_, RemotePlayer *player_, session_t p
 	UnitSAO(env_, v3f(0,0,0)),
 	m_player(player_),
 	m_peer_id_initial(peer_id_),
+	m_guid(player_->getName()),
 	m_is_singleplayer(is_singleplayer)
 {
 	SANITY_CHECK(m_peer_id_initial != PEER_ID_INEXISTENT);
@@ -417,6 +418,11 @@ void PlayerSAO::setPlayerYaw(const float yaw)
 	UnitSAO::setRotation(rotation);
 }
 
+GUId PlayerSAO::getGuid()
+{
+	return m_guid;
+}
+
 void PlayerSAO::setFov(const float fov)
 {
 	if (m_player && fov != m_fov)
diff --git a/src/server/player_sao.h b/src/server/player_sao.h
index b26304589..a7a8448d2 100644
--- a/src/server/player_sao.h
+++ b/src/server/player_sao.h
@@ -93,6 +93,7 @@ public:
 	void addPos(const v3f &added_pos) override;
 	void moveTo(v3f pos, bool continuous) override;
 	void setPlayerYaw(const float yaw);
+	GUId getGuid() override;
 	// Data should not be sent at player initialization
 	void setPlayerYawAndSend(const float yaw);
 	void setLookPitch(const float pitch);
@@ -195,6 +196,7 @@ private:
 
 	RemotePlayer *m_player = nullptr;
 	session_t m_peer_id_initial = 0; ///< only used to initialize RemotePlayer
+	GUId m_guid;
 
 	// Cheat prevention
 	LagPool m_dig_pool;
diff --git a/src/server/serveractiveobject.h b/src/server/serveractiveobject.h
index 4d620b768..9fe97b343 100644
--- a/src/server/serveractiveobject.h
+++ b/src/server/serveractiveobject.h
@@ -24,6 +24,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "irrlichttypes_bloated.h"
 #include "activeobject.h"
 #include "itemgroup.h"
+#include "guid.h"
 #include "util/container.h"
 
 
@@ -160,6 +161,9 @@ public:
 	virtual u16 getHP() const
 	{ return 0; }
 
+	// Returns always the same unique string for the same object.
+	virtual GUId getGuid() = 0;
+
 	virtual void setArmorGroups(const ItemGroupList &armor_groups)
 	{}
 	virtual const ItemGroupList &getArmorGroups() const
@@ -235,6 +239,11 @@ public:
 		about handling it.
 	*/
 	bool m_static_exists = false;
+	/*
+		Set this to true when the staticdata needs to be saved even though it
+		looks like it did not change.
+	*/
+	bool m_force_write_staticdata = false;
 	/*
 		The block from which the object was loaded from, and in which
 		a copy of the static data resides.
diff --git a/src/serverenvironment.cpp b/src/serverenvironment.cpp
index 8a7b568eb..a8f96ff23 100644
--- a/src/serverenvironment.cpp
+++ b/src/serverenvironment.cpp
@@ -448,6 +448,8 @@ ServerEnvironment::ServerEnvironment(std::unique_ptr<ServerMap> map,
 
 	m_active_object_gauge = mb->addGauge(
 		"minetest_env_active_objects", "Number of active objects");
+
+	m_guid_generator.setServerEnvironment(this);
 }
 
 void ServerEnvironment::init()
@@ -1889,6 +1891,8 @@ u16 ServerEnvironment::addActiveObjectRaw(std::unique_ptr<ServerActiveObject> ob
 	// Post-initialize object
 	// Note that this can change the value of isStaticAllowed() in case of LuaEntitySAO
 	object->addedToEnvironment(dtime_s);
+	// After post-initialize, GUID is known
+	m_script->addObjectByGuid(object);
 
 	// Activate object
 	if (object->m_static_exists)
@@ -2199,7 +2203,9 @@ void ServerEnvironment::deactivateFarObjects(const bool _force_delete)
 				While changes are always saved, blocks are only marked as modified
 				if the object has moved or different staticdata. (see above)
 			*/
-			bool shall_be_written = (!stays_in_same_block || data_changed);
+			bool shall_be_written = (!stays_in_same_block || data_changed ||
+					obj->m_force_write_staticdata);
+			obj->m_force_write_staticdata = false;
 			u32 reason = shall_be_written ? MOD_REASON_STATIC_DATA_CHANGED : MOD_REASON_UNKNOWN;
 
 			// Delete old static object
diff --git a/src/serverenvironment.h b/src/serverenvironment.h
index d5d45d0f4..42dc603a4 100644
--- a/src/serverenvironment.h
+++ b/src/serverenvironment.h
@@ -25,6 +25,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "activeobject.h"
 #include "environment.h"
 #include "servermap.h"
+#include "guid.h"
+#include "map.h"
 #include "settings.h"
 #include "server/activeobjectmgr.h"
 #include "util/numeric.h"
@@ -238,6 +240,9 @@ public:
 	float getSendRecommendedInterval()
 	{ return m_recommended_send_interval; }
 
+	GUIdGenerator & getGUIdGenerator()
+	{ return m_guid_generator; }
+
 	// Save players
 	void saveLoadedPlayers(bool force = false);
 	void savePlayer(RemotePlayer *player);
@@ -463,6 +468,10 @@ private:
 	server::ActiveObjectMgr m_ao_manager;
 	// on_mapblocks_changed map event receiver
 	OnMapblocksChangedReceiver m_on_mapblocks_changed_receiver;
+	// Generator for luaentity guids
+	GUIdGenerator m_guid_generator;
+	// World path
+	const std::string m_path_world;
 	// Outgoing network message buffer for active objects
 	std::queue<ActiveObjectMessage> m_active_object_messages;
 	// Some timers
diff --git a/src/unittest/mock_serveractiveobject.h b/src/unittest/mock_serveractiveobject.h
index 78e3df8af..e74ef0264 100644
--- a/src/unittest/mock_serveractiveobject.h
+++ b/src/unittest/mock_serveractiveobject.h
@@ -29,4 +29,5 @@ public:
 	virtual bool getCollisionBox(aabb3f *toset) const { return false; }
 	virtual bool getSelectionBox(aabb3f *toset) const { return false; }
 	virtual bool collideWithObjects() const { return false; }
+	virtual std::string getGuid() {return "";}
 };
diff --git a/src/unittest/test_moveaction.cpp b/src/unittest/test_moveaction.cpp
index 0720ba267..3ed8f184c 100644
--- a/src/unittest/test_moveaction.cpp
+++ b/src/unittest/test_moveaction.cpp
@@ -31,18 +31,18 @@ public:
 
 	void runTests(IGameDef *gamedef);
 
-	void testMove(ServerActiveObject *obj, IGameDef *gamedef);
-	void testMoveFillStack(ServerActiveObject *obj, IGameDef *gamedef);
-	void testMoveSomewhere(ServerActiveObject *obj, IGameDef *gamedef);
-	void testMoveUnallowed(ServerActiveObject *obj, IGameDef *gamedef);
-	void testMovePartial(ServerActiveObject *obj, IGameDef *gamedef);
+	void testMove(MockServerActiveObject *obj, IGameDef *gamedef);
+	void testMoveFillStack(MockServerActiveObject *obj, IGameDef *gamedef);
+	void testMoveSomewhere(MockServerActiveObject *obj, IGameDef *gamedef);
+	void testMoveUnallowed(MockServerActiveObject *obj, IGameDef *gamedef);
+	void testMovePartial(MockServerActiveObject *obj, IGameDef *gamedef);
 
-	void testSwap(ServerActiveObject *obj, IGameDef *gamedef);
-	void testSwapFromUnallowed(ServerActiveObject *obj, IGameDef *gamedef);
-	void testSwapToUnallowed(ServerActiveObject *obj, IGameDef *gamedef);
+	void testSwap(MockServerActiveObject *obj, IGameDef *gamedef);
+	void testSwapFromUnallowed(MockServerActiveObject *obj, IGameDef *gamedef);
+	void testSwapToUnallowed(MockServerActiveObject *obj, IGameDef *gamedef);
 
-	void testCallbacks(ServerActiveObject *obj, Server *server);
-	void testCallbacksSwap(ServerActiveObject *obj, Server *server);
+	void testCallbacks(MockServerActiveObject *obj, Server *server);
+	void testCallbacksSwap(MockServerActiveObject *obj, Server *server);
 };
 
 static TestMoveAction g_test_instance;
@@ -97,7 +97,7 @@ static void apply_action(const char *s, InventoryManager *inv, ServerActiveObjec
 	delete action;
 }
 
-void TestMoveAction::testMove(ServerActiveObject *obj, IGameDef *gamedef)
+void TestMoveAction::testMove(MockServerActiveObject *obj, IGameDef *gamedef)
 {
 	MockInventoryManager inv(gamedef);
 
@@ -110,7 +110,7 @@ void TestMoveAction::testMove(ServerActiveObject *obj, IGameDef *gamedef)
 	UASSERT(inv.p2.getList("main")->getItem(0).getItemString() == "default:stone 20");
 }
 
-void TestMoveAction::testMoveFillStack(ServerActiveObject *obj, IGameDef *gamedef)
+void TestMoveAction::testMoveFillStack(MockServerActiveObject *obj, IGameDef *gamedef)
 {
 	MockInventoryManager inv(gamedef);
 
@@ -130,7 +130,7 @@ void TestMoveAction::testMoveFillStack(ServerActiveObject *obj, IGameDef *gamede
 	UASSERT(list->getItem(1).getItemString() == "default:stone 200");
 }
 
-void TestMoveAction::testMoveSomewhere(ServerActiveObject *obj, IGameDef *gamedef)
+void TestMoveAction::testMoveSomewhere(MockServerActiveObject *obj, IGameDef *gamedef)
 {
 	MockInventoryManager inv(gamedef);
 
@@ -146,7 +146,7 @@ void TestMoveAction::testMoveSomewhere(ServerActiveObject *obj, IGameDef *gamede
 	UASSERT(inv.p2.getList("main")->getItem(2).getItemString() == "default:stone 99");
 }
 
-void TestMoveAction::testMoveUnallowed(ServerActiveObject *obj, IGameDef *gamedef)
+void TestMoveAction::testMoveUnallowed(MockServerActiveObject *obj, IGameDef *gamedef)
 {
 	MockInventoryManager inv(gamedef);
 
@@ -159,7 +159,7 @@ void TestMoveAction::testMoveUnallowed(ServerActiveObject *obj, IGameDef *gamede
 	UASSERT(inv.p2.getList("main")->getItem(0).empty())
 }
 
-void TestMoveAction::testMovePartial(ServerActiveObject *obj, IGameDef *gamedef)
+void TestMoveAction::testMovePartial(MockServerActiveObject *obj, IGameDef *gamedef)
 {
 	MockInventoryManager inv(gamedef);
 
@@ -173,7 +173,7 @@ void TestMoveAction::testMovePartial(ServerActiveObject *obj, IGameDef *gamedef)
 	UASSERT(inv.p2.getList("main")->getItem(0).getItemString() == "default:takeput_max_5 5");
 }
 
-void TestMoveAction::testSwap(ServerActiveObject *obj, IGameDef *gamedef)
+void TestMoveAction::testSwap(MockServerActiveObject *obj, IGameDef *gamedef)
 {
 	MockInventoryManager inv(gamedef);
 
@@ -186,7 +186,7 @@ void TestMoveAction::testSwap(ServerActiveObject *obj, IGameDef *gamedef)
 	UASSERT(inv.p2.getList("main")->getItem(0).getItemString() == "default:stone 50");
 }
 
-void TestMoveAction::testSwapFromUnallowed(ServerActiveObject *obj, IGameDef *gamedef)
+void TestMoveAction::testSwapFromUnallowed(MockServerActiveObject *obj, IGameDef *gamedef)
 {
 	MockInventoryManager inv(gamedef);
 
@@ -199,7 +199,7 @@ void TestMoveAction::testSwapFromUnallowed(ServerActiveObject *obj, IGameDef *ga
 	UASSERT(inv.p2.getList("main")->getItem(0).getItemString() == "default:brick 60");
 }
 
-void TestMoveAction::testSwapToUnallowed(ServerActiveObject *obj, IGameDef *gamedef)
+void TestMoveAction::testSwapToUnallowed(MockServerActiveObject *obj, IGameDef *gamedef)
 {
 	MockInventoryManager inv(gamedef);
 
@@ -230,7 +230,7 @@ static bool check_function(lua_State *L, bool expect_swap)
 	return ok;
 }
 
-void TestMoveAction::testCallbacks(ServerActiveObject *obj, Server *server)
+void TestMoveAction::testCallbacks(MockServerActiveObject *obj, Server *server)
 {
 	server->m_inventory_mgr = std::make_unique<MockInventoryManager>(server);
 	MockInventoryManager &inv = *(MockInventoryManager *)server->getInventoryMgr();
@@ -246,7 +246,7 @@ void TestMoveAction::testCallbacks(ServerActiveObject *obj, Server *server)
 	server->m_inventory_mgr.reset();
 }
 
-void TestMoveAction::testCallbacksSwap(ServerActiveObject *obj, Server *server)
+void TestMoveAction::testCallbacksSwap(MockServerActiveObject *obj, Server *server)
 {
 	server->m_inventory_mgr = std::make_unique<MockInventoryManager>(server);
 	MockInventoryManager &inv = *(MockInventoryManager *)server->getInventoryMgr();
diff --git a/src/unittest/test_serveractiveobjectmgr.cpp b/src/unittest/test_serveractiveobjectmgr.cpp
index 7f0ca84cb..0ec66d5f2 100644
--- a/src/unittest/test_serveractiveobjectmgr.cpp
+++ b/src/unittest/test_serveractiveobjectmgr.cpp
@@ -26,7 +26,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "profiler.h"
 
-
 class TestServerActiveObjectMgr : public TestBase
 {
 public: