diff --git a/src/lib.rs b/src/lib.rs
index 1354e7aed..b3eca7c5c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,62 @@
 #[macro_use] extern crate log;
+extern crate ethcore_util;
+
+use ethcore_util::hash::*;
+
+pub type Bytes = Vec<u8>;
+pub type Uint256 = Hash256;
+pub type LogBloom = Hash4096;
+
+pub const ZERO_UINT256: Uint256 = Hash256([0x00; 32]);
+pub const ZERO_ADDRESS: Address = Address([0x00; 20]);
+pub const BAD_UINT256: Uint256 = Hash256([0xff; 32]);
+pub const ZERO_HASH256: Hash256 = Hash256([0x00; 32]);
+pub const ZERO_LOGBLOOM: LogBloom = Hash4096([0x00; 512]);
+
+#[derive(Debug)]
+pub struct Header {
+	parent_hash: Hash256,
+	timestamp: Uint256,
+	number: Uint256,
+	author: Address,
+
+	transactions_root: Hash256,
+	uncles_hash: Hash256,
+	extra_data_hash: Hash256,
+
+	state_root: Hash256,
+	receipts_root: Hash256,
+	log_bloom: LogBloom,
+	gas_used: Uint256,
+	gas_limit: Uint256,
+
+	difficulty: Uint256,
+	seal: Vec<Bytes>,
+}
+
+impl Header {
+	pub fn new() -> Header {
+		Header {
+			parent_hash: ZERO_UINT256,
+			timestamp: BAD_UINT256,
+			number: ZERO_UINT256,
+			author: ZERO_ADDRESS,
+
+			transactions_root: ZERO_HASH256,
+			uncles_hash: ZERO_HASH256,
+			extra_data_hash: ZERO_HASH256,
+
+			state_root: ZERO_HASH256,
+			receipts_root: ZERO_HASH256,
+			log_bloom: ZERO_LOGBLOOM,
+			gas_used: ZERO_UINT256,
+			gas_limit: ZERO_UINT256,
+
+			difficulty: ZERO_UINT256,
+			seal: vec![],
+		}
+	}
+}
 
 /// Silly function to return 69.
 ///
@@ -11,4 +69,3 @@ pub fn sixtynine() -> i32 {
 	debug!("Hello world!");
 	69
 }
-