diff --git a/library/terra_material_cache.cpp b/library/terra_material_cache.cpp
index e2dfd82..c26bc22 100644
--- a/library/terra_material_cache.cpp
+++ b/library/terra_material_cache.cpp
@@ -29,6 +29,19 @@ void TerraMaterialCache::set_initialized(const bool value) {
 	_initialized = value;
 }
 
+int TerraMaterialCache::get_ref_count() {
+	return _ref_count;
+}
+void TerraMaterialCache::set_ref_count(const int value) {
+	_ref_count = value;
+}
+void TerraMaterialCache::inc_ref_count() {
+	_ref_count += 1;
+}
+void TerraMaterialCache::dec_ref_count() {
+	_ref_count -= 1;
+}
+
 //Materials
 Ref<Material> TerraMaterialCache::material_get(const int index) {
 	ERR_FAIL_INDEX_V(index, _materials.size(), Ref<Material>(NULL));
@@ -143,7 +156,7 @@ void TerraMaterialCache::setup_material_albedo(Ref<Texture> texture) {
 }
 
 TerraMaterialCache::TerraMaterialCache() {
-	material_users = 0;
+	_ref_count = 0;
 	_initialized = false;
 }
 
@@ -157,6 +170,12 @@ void TerraMaterialCache::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_initialized", "value"), &TerraMaterialCache::set_initialized);
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "initialized"), "set_initialized", "get_initialized");
 
+	ClassDB::bind_method(D_METHOD("get_ref_count"), &TerraMaterialCache::get_ref_count);
+	ClassDB::bind_method(D_METHOD("set_ref_count", "value"), &TerraMaterialCache::set_ref_count);
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "mat_ref_count"), "set_ref_count", "get_ref_count");
+	ClassDB::bind_method(D_METHOD("inc_ref_count"), &TerraMaterialCache::inc_ref_count);
+	ClassDB::bind_method(D_METHOD("dec_ref_count"), &TerraMaterialCache::dec_ref_count);
+
 	BIND_VMETHOD(MethodInfo("_setup_material_albedo", PropertyInfo(Variant::OBJECT, "texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture")));
 
 	ClassDB::bind_method(D_METHOD("material_get", "index"), &TerraMaterialCache::material_get);
diff --git a/library/terra_material_cache.h b/library/terra_material_cache.h
index f8240cd..a668c01 100644
--- a/library/terra_material_cache.h
+++ b/library/terra_material_cache.h
@@ -51,6 +51,11 @@ public:
 	bool get_initialized();
 	void set_initialized(const bool value);
 
+	int get_ref_count();
+	void set_ref_count(const int value);
+	void inc_ref_count();
+	void dec_ref_count();
+
 	Ref<Material> material_get(const int index);
 	Ref<Material> material_lod_get(const int index);
 	void material_add(const Ref<Material> &value);
@@ -84,8 +89,8 @@ protected:
 
 	Vector<Ref<TerraSurface>> _surfaces;
 	Vector<Ref<Material>> _materials;
-	
-	int material_users;
+
+	int _ref_count;
 };
 
 #endif
diff --git a/library/terraman_library.cpp b/library/terraman_library.cpp
index f6e4709..6a39880 100644
--- a/library/terraman_library.cpp
+++ b/library/terraman_library.cpp
@@ -84,6 +84,12 @@ Ref<TerraMaterialCache> TerramanLibrary::_material_cache_get(const int key) {
 	ERR_FAIL_V_MSG(Ref<TerraMaterialCache>(), "This TerramanLibrary doesn't support cached materials!");
 }
 
+void TerramanLibrary::material_cache_unref(const int key) {
+	call("_material_cache_unref", key);
+}
+void TerramanLibrary::_material_cache_unref(const int key) {
+}
+
 void TerramanLibrary::material_add(const Ref<Material> &value) {
 	ERR_FAIL_COND(!value.is_valid());
 
@@ -158,6 +164,12 @@ Ref<TerraMaterialCache> TerramanLibrary::_liquid_material_cache_get(const int ke
 	ERR_FAIL_V_MSG(Ref<TerraMaterialCache>(), "This TerramanLibrary doesn't support cached liquid materials!");
 }
 
+void TerramanLibrary::liquid_material_cache_unref(const int key) {
+	call("_liquid_material_cache_unref", key);
+}
+void TerramanLibrary::_liquid_material_cache_unref(const int key) {
+}
+
 void TerramanLibrary::liquid_material_add(const Ref<Material> &value) {
 	ERR_FAIL_COND(!value.is_valid());
 
@@ -232,6 +244,12 @@ Ref<TerraMaterialCache> TerramanLibrary::_prop_material_cache_get(const int key)
 	ERR_FAIL_V_MSG(Ref<TerraMaterialCache>(), "This TerramanLibrary doesn't support cached prop materials!");
 }
 
+void TerramanLibrary::prop_material_cache_unref(const int key) {
+	call("_prop_material_cache_unref", key);
+}
+void TerramanLibrary::_prop_material_cache_unref(const int key) {
+}
+
 void TerramanLibrary::prop_material_add(const Ref<Material> &value) {
 	ERR_FAIL_COND(!value.is_valid());
 
@@ -351,7 +369,8 @@ void TerramanLibrary::_bind_methods() {
 	BIND_VMETHOD(MethodInfo("_setup_material_albedo", PropertyInfo(Variant::INT, "material_index"), PropertyInfo(Variant::OBJECT, "texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture")));
 
 	BIND_VMETHOD(MethodInfo("_material_cache_get_key", PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerraChunk")));
-	BIND_VMETHOD(MethodInfo("_material_cache_get", PropertyInfo(Variant::OBJECT, "key", PROPERTY_HINT_RESOURCE_TYPE, "TerraMaterialCache")));
+	BIND_VMETHOD(MethodInfo(PropertyInfo(Variant::OBJECT, "ret", PROPERTY_HINT_RESOURCE_TYPE, "TerraMaterialCache"), "_material_cache_get", PropertyInfo(Variant::INT, "key")));
+	BIND_VMETHOD(MethodInfo("_material_cache_unref", PropertyInfo(Variant::INT, "key")));
 
 	ClassDB::bind_method(D_METHOD("material_get", "index"), &TerramanLibrary::material_get);
 	ClassDB::bind_method(D_METHOD("material_lod_get", "index"), &TerramanLibrary::material_lod_get);
@@ -360,6 +379,8 @@ void TerramanLibrary::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("_material_cache_get_key", "chunk"), &TerramanLibrary::_material_cache_get_key);
 	ClassDB::bind_method(D_METHOD("material_cache_get", "key"), &TerramanLibrary::material_cache_get);
 	ClassDB::bind_method(D_METHOD("_material_cache_get", "key"), &TerramanLibrary::_material_cache_get);
+	ClassDB::bind_method(D_METHOD("material_cache_unref", "key"), &TerramanLibrary::material_cache_unref);
+	ClassDB::bind_method(D_METHOD("_material_cache_unref", "key"), &TerramanLibrary::_material_cache_unref);
 
 	ClassDB::bind_method(D_METHOD("material_add", "value"), &TerramanLibrary::material_add);
 	ClassDB::bind_method(D_METHOD("material_set", "index", "value"), &TerramanLibrary::material_set);
@@ -372,7 +393,8 @@ void TerramanLibrary::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "materials", PROPERTY_HINT_NONE, "17/17:Material", PROPERTY_USAGE_DEFAULT, "Material"), "materials_set", "materials_get");
 
 	BIND_VMETHOD(MethodInfo("_liquid_material_cache_get_key", PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerraChunk")));
-	BIND_VMETHOD(MethodInfo("_liquid_material_cache_get", PropertyInfo(Variant::OBJECT, "key", PROPERTY_HINT_RESOURCE_TYPE, "TerraMaterialCache")));
+	BIND_VMETHOD(MethodInfo(PropertyInfo(Variant::OBJECT, "ret", PROPERTY_HINT_RESOURCE_TYPE, "TerraMaterialCache"), "_liquid_material_cache_get", PropertyInfo(Variant::INT, "key")));
+	BIND_VMETHOD(MethodInfo("_liquid_material_cache_unref", PropertyInfo(Variant::INT, "key")));
 
 	ClassDB::bind_method(D_METHOD("liquid_material_get", "index"), &TerramanLibrary::liquid_material_get);
 	ClassDB::bind_method(D_METHOD("liquid_material_lod_get", "index"), &TerramanLibrary::liquid_material_lod_get);
@@ -381,6 +403,8 @@ void TerramanLibrary::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("_liquid_material_cache_get_key", "chunk"), &TerramanLibrary::_liquid_material_cache_get_key);
 	ClassDB::bind_method(D_METHOD("liquid_material_cache_get", "key"), &TerramanLibrary::liquid_material_cache_get);
 	ClassDB::bind_method(D_METHOD("_liquid_material_cache_get", "key"), &TerramanLibrary::_liquid_material_cache_get);
+	ClassDB::bind_method(D_METHOD("liquid_material_cache_unref", "key"), &TerramanLibrary::liquid_material_cache_unref);
+	ClassDB::bind_method(D_METHOD("_liquid_material_cache_unref", "key"), &TerramanLibrary::_liquid_material_cache_unref);
 
 	ClassDB::bind_method(D_METHOD("liquid_material_add", "value"), &TerramanLibrary::liquid_material_add);
 	ClassDB::bind_method(D_METHOD("liquid_material_set", "index", "value"), &TerramanLibrary::liquid_material_set);
@@ -393,7 +417,8 @@ void TerramanLibrary::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "liquid_materials", PROPERTY_HINT_NONE, "17/17:Material", PROPERTY_USAGE_DEFAULT, "Material"), "liquid_materials_set", "liquid_materials_get");
 
 	BIND_VMETHOD(MethodInfo("_prop_material_cache_get_key", PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerraChunk")));
-	BIND_VMETHOD(MethodInfo("_prop_material_cache_get", PropertyInfo(Variant::OBJECT, "key", PROPERTY_HINT_RESOURCE_TYPE, "TerraMaterialCache")));
+	BIND_VMETHOD(MethodInfo(PropertyInfo(Variant::OBJECT, "ret", PROPERTY_HINT_RESOURCE_TYPE, "TerraMaterialCache"), "_prop_material_cache_get", PropertyInfo(Variant::INT, "key")));
+	BIND_VMETHOD(MethodInfo("_prop_material_cache_unref", PropertyInfo(Variant::INT, "key")));
 
 	ClassDB::bind_method(D_METHOD("prop_material_get", "index"), &TerramanLibrary::prop_material_get);
 	ClassDB::bind_method(D_METHOD("prop_material_lod_get", "index"), &TerramanLibrary::prop_material_lod_get);
@@ -402,6 +427,8 @@ void TerramanLibrary::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("_prop_material_cache_get_key", "chunk"), &TerramanLibrary::_prop_material_cache_get_key);
 	ClassDB::bind_method(D_METHOD("prop_material_cache_get", "key"), &TerramanLibrary::prop_material_cache_get);
 	ClassDB::bind_method(D_METHOD("_prop_material_cache_get", "key"), &TerramanLibrary::_prop_material_cache_get);
+	ClassDB::bind_method(D_METHOD("prop_material_cache_unref", "key"), &TerramanLibrary::prop_material_cache_unref);
+	ClassDB::bind_method(D_METHOD("_prop_material_cache_unref", "key"), &TerramanLibrary::_prop_material_cache_unref);
 
 	ClassDB::bind_method(D_METHOD("prop_material_add", "value"), &TerramanLibrary::prop_material_add);
 	ClassDB::bind_method(D_METHOD("prop_material_set", "index", "value"), &TerramanLibrary::prop_material_set);
diff --git a/library/terraman_library.h b/library/terraman_library.h
index 1ed71a7..c9ae933 100644
--- a/library/terraman_library.h
+++ b/library/terraman_library.h
@@ -76,6 +76,8 @@ public:
 	virtual void _material_cache_get_key(Ref<TerraChunk> chunk);
 	Ref<TerraMaterialCache> material_cache_get(const int key);
 	virtual Ref<TerraMaterialCache> _material_cache_get(const int key);
+	void material_cache_unref(const int key);
+	virtual void _material_cache_unref(const int key);
 
 	void material_add(const Ref<Material> &value);
 	void material_set(const int index, const Ref<Material> &value);
@@ -93,6 +95,8 @@ public:
 	virtual void _liquid_material_cache_get_key(Ref<TerraChunk> chunk);
 	Ref<TerraMaterialCache> liquid_material_cache_get(const int key);
 	virtual Ref<TerraMaterialCache> _liquid_material_cache_get(const int key);
+	void liquid_material_cache_unref(const int key);
+	virtual void _liquid_material_cache_unref(const int key);
 
 	void liquid_material_add(const Ref<Material> &value);
 	void liquid_material_set(const int index, const Ref<Material> &value);
@@ -110,6 +114,8 @@ public:
 	virtual void _prop_material_cache_get_key(Ref<TerraChunk> chunk);
 	Ref<TerraMaterialCache> prop_material_cache_get(const int key);
 	virtual Ref<TerraMaterialCache> _prop_material_cache_get(const int key);
+	void prop_material_cache_unref(const int key);
+	virtual void _prop_material_cache_unref(const int key);
 
 	void prop_material_add(const Ref<Material> &value);
 	void prop_material_set(const int index, const Ref<Material> &value);
@@ -157,9 +163,9 @@ protected:
 	static void _bind_methods();
 
 	bool _initialized;
-	Vector<Ref<Material> > _materials;
-	Vector<Ref<Material> > _liquid_materials;
-	Vector<Ref<Material> > _prop_materials;
+	Vector<Ref<Material>> _materials;
+	Vector<Ref<Material>> _liquid_materials;
+	Vector<Ref<Material>> _prop_materials;
 };
 
 #endif // TERRA_LIBRARY_H
diff --git a/library/terraman_library_merger_pcm.cpp b/library/terraman_library_merger_pcm.cpp
index 7b45167..179ad0f 100644
--- a/library/terraman_library_merger_pcm.cpp
+++ b/library/terraman_library_merger_pcm.cpp
@@ -104,8 +104,14 @@ void TerramanLibraryMergerPCM::_material_cache_get_key(Ref<TerraChunk> chunk) {
 	_cache_mutex.lock();
 
 	if (_material_cache.has(hash)) {
+		Ref<TerraMaterialCachePCM> cc = _material_cache[hash];
+
+		if (cc.is_valid()) {
+			cc->inc_ref_count();
+		}
+
 		_cache_mutex.unlock();
-		
+
 		return;
 	}
 
@@ -113,6 +119,7 @@ void TerramanLibraryMergerPCM::_material_cache_get_key(Ref<TerraChunk> chunk) {
 
 	Ref<TerraMaterialCachePCM> cache;
 	cache.instance();
+	cache->inc_ref_count();
 
 	cache->set_texture_flags(get_texture_flags());
 	cache->set_max_atlas_size(get_max_atlas_size());
@@ -171,6 +178,28 @@ Ref<TerraMaterialCache> TerramanLibraryMergerPCM::_material_cache_get(const int
 	return _material_cache[key];
 }
 
+void TerramanLibraryMergerPCM::_material_cache_unref(const int key) {
+	_cache_mutex.lock();
+
+	if (!_material_cache.has(key)) {
+		return;
+	}
+
+	Ref<TerraMaterialCachePCM> cc = _material_cache[key];
+
+	if (!cc.is_valid()) {
+		return;
+	}
+
+	cc->dec_ref_count();
+
+	if (cc->get_ref_count() <= 0) {
+		_material_cache.erase(key);
+	}
+
+	_cache_mutex.unlock();
+}
+
 int TerramanLibraryMergerPCM::get_texture_flags() const {
 	return _packer->get_texture_flags();
 }
diff --git a/library/terraman_library_merger_pcm.h b/library/terraman_library_merger_pcm.h
index 48f731a..96a4076 100644
--- a/library/terraman_library_merger_pcm.h
+++ b/library/terraman_library_merger_pcm.h
@@ -56,6 +56,7 @@ public:
 	bool _supports_caching();
 	void _material_cache_get_key(Ref<TerraChunk> chunk);
 	Ref<TerraMaterialCache> _material_cache_get(const int key);
+	void _material_cache_unref(const int key);
 
 	int get_texture_flags() const;
 	void set_texture_flags(const int flags);
diff --git a/world/terra_chunk.cpp b/world/terra_chunk.cpp
index 903c717..c7f91cd 100644
--- a/world/terra_chunk.cpp
+++ b/world/terra_chunk.cpp
@@ -938,6 +938,12 @@ void TerraChunk::enter_tree() {
 void TerraChunk::exit_tree() {
 	_is_in_tree = false;
 
+	if (_library.is_valid() && _library->supports_caching()) {
+		if (material_cache_key_has()) {
+			_library->material_cache_unref(material_cache_key_get());
+		}
+	}
+
 	if (has_method("_exit_tree"))
 		call("_exit_tree");
 }