diff --git a/src/map.rs b/src/map.rs
index a2085af..9513daf 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -313,7 +313,7 @@ fn collect_spacial_blocks(
 			model_count+=1;
 			models.push(model);
 		});
-		let id=BlockId::new(block_headers.len() as u32);
+		let id=BlockId::new(block_headers.len() as u32+1);
 		block_headers.push(SpacialBlockHeader{
 			id,
 			extents,
@@ -362,7 +362,7 @@ pub fn write_map<W:BinWriterExt>(mut writer:W,map:strafesnet_common::map::Comple
 	let mut sequential_block_data=Vec::new();
 	let mut cursor_to_data=std::io::Cursor::new(&mut sequential_block_data);
 	collect_spacial_blocks(&mut block_location,&mut spacial_blocks,&mut cursor_to_data,bvh)?;
-	let mut block_count=spacial_blocks.len() as u32;//continue block id
+	let mut block_count=spacial_blocks.len() as u32+1;//continue block id
 	let mut resource_blocks=Vec::new();//for map header
 	//meshes
 	for mesh in map.meshes.into_iter(){
@@ -400,9 +400,6 @@ pub fn write_map<W:BinWriterExt>(mut writer:W,map:strafesnet_common::map::Comple
 		attributes:map.attributes.into_iter().map(Into::into).collect(),
 		render_configs:map.render_configs.into_iter().map(Into::into).collect(),
 	};
-	//the map header is a block!
-	block_count+=1;
-	assert_eq!(block_count as usize+1,block_location.len());
 	let mut file_header=crate::file::Header{
 		fourcc:crate::file::FourCC::Map,
 		version:0,