diff --git a/src/client/client.cpp b/src/client/client.cpp
index 0f9ee8a6b..b350e1cc5 100644
--- a/src/client/client.cpp
+++ b/src/client/client.cpp
@@ -563,7 +563,8 @@ void Client::step(float dtime)
 			std::vector<MinimapMapblock*> minimap_mapblocks;
 			bool do_mapper_update = true;
 
-			MapSector *sector = m_env.getMap().emergeSector(v2s16(r.p.X, r.p.Z));
+			ClientMap &map = m_env.getClientMap();
+			MapSector *sector = map.emergeSector(v2s16(r.p.X, r.p.Z));
 
 			MapBlock *block = sector->getBlockNoCreateNoEx(r.p.Y);
 
@@ -575,6 +576,8 @@ void Client::step(float dtime)
 
 			if (block) {
 				// Delete the old mesh
+				if (block->mesh)
+					map.invalidateMapBlockMesh(block->mesh);
 				delete block->mesh;
 				block->mesh = nullptr;
 				block->solid_sides = r.solid_sides;
@@ -589,10 +592,9 @@ void Client::step(float dtime)
 						if (r.mesh->getMesh(l)->getMeshBufferCount() != 0)
 							is_empty = false;
 
-					// <- invalidate here?
-					if (is_empty)
+					if (is_empty) {
 						delete r.mesh;
-					else {
+					} else {
 						// Replace with the new mesh
 						block->mesh = r.mesh;
 						if (r.urgent)
diff --git a/src/client/clientmap.cpp b/src/client/clientmap.cpp
index 0a746fa7d..0a5a3f963 100644
--- a/src/client/clientmap.cpp
+++ b/src/client/clientmap.cpp
@@ -841,12 +841,12 @@ static u32 transformBuffersToDrawOrder(
 		driver->removeHardwareBuffer(buf->getIndexBuffer());
 	}
 
+	// TODO: explain and document
 	std::string kkk;
 	std::sort(to_merge.begin(), to_merge.end(), [] (const auto &l, const auto &r) {
-		return l.second < r.second;
+		return static_cast<void*>(l.second) < static_cast<void*>(r.second);
 	});
 	for (auto &it : to_merge) {
-		// TODO?: big assumptions here
 		kkk.append(reinterpret_cast<const char*>(&it.second), sizeof(it.second));
 	}
 
@@ -1092,6 +1092,55 @@ void ClientMap::renderMap(video::IVideoDriver* driver, s32 pass)
 	g_profiler->avg(prefix + "material swaps [#]", material_swaps);
 }
 
+void ClientMap::invalidateMapBlockMesh(MapBlockMesh *mesh)
+{
+	ScopeProfiler sp(g_profiler, "CM::invalidateMapBlockMesh", SPT_ADD, PRECISION_MICRO);
+
+	// find all buffers
+	MeshBufListMaps tmp;
+	tmp.addFromBlock(v3s16(), mesh, getSceneManager()->getVideoDriver());
+
+	std::vector<void*> to_delete;
+	void *maxp = 0;
+	for (auto &it : tmp.maps) {
+		for (auto &it2 : it) {
+			for (auto &it3 : it2.second) {
+				void *const p = it3.second;
+				to_delete.push_back(p);
+				maxp = std::max(maxp, p);
+			}
+		}
+	}
+
+	g_profiler->add("CM::invalidateMapBlockMesh to_delete", to_delete.size());
+
+	if (to_delete.empty())
+		return;
+
+	// remove matching cache elements
+	u32 deleted = 0;
+	for (auto it = m_dynamic_buffers.begin(); it != m_dynamic_buffers.end(); ) {
+		const std::string &key = it->first;
+		assert(key.size() % sizeof(void*) == 0);
+		for (size_t off = 0; off < key.size(); off += sizeof(void*)) {
+			void *v;
+			memcpy(&v, &key[off], sizeof(void*));
+			if (v > maxp) // early exit
+				break;
+			if (CONTAINS(to_delete, v)) {
+				it = m_dynamic_buffers.erase(it);
+				deleted++;
+				goto continue_outer;
+			}
+		}
+		it++;
+		continue_outer:
+		continue;
+	}
+
+	g_profiler->add("CM::invalidateMapBlockMesh deleted", deleted);
+}
+
 static bool getVisibleBrightness(Map *map, const v3f &p0, v3f dir, float step,
 	float step_multiplier, float start_distance, float end_distance,
 	const NodeDefManager *ndef, u32 daylight_factor, float sunlight_min_d,
diff --git a/src/client/clientmap.h b/src/client/clientmap.h
index dae97b417..b76e513e2 100644
--- a/src/client/clientmap.h
+++ b/src/client/clientmap.h
@@ -103,6 +103,8 @@ public:
 
 	void renderPostFx(CameraMode cam_mode);
 
+	void invalidateMapBlockMesh(MapBlockMesh *mesh);
+
 	// For debug printing
 	void PrintInfo(std::ostream &out) override;
 
diff --git a/src/defaultsettings.cpp b/src/defaultsettings.cpp
index 47dc2ad3f..4851ebf73 100644
--- a/src/defaultsettings.cpp
+++ b/src/defaultsettings.cpp
@@ -104,7 +104,7 @@ void set_default_settings()
 	settings->setDefault("sound_extensions_blacklist", "");
 	settings->setDefault("mesh_generation_interval", "0");
 	settings->setDefault("mesh_generation_threads", "0");
-	settings->setDefault("mesh_buffer_min_vertices", "100");
+	settings->setDefault("mesh_buffer_min_vertices", "300");
 	settings->setDefault("free_move", "false");
 	settings->setDefault("pitch_move", "false");
 	settings->setDefault("fast_move", "false");