diff --git a/core/src/genesis.rs b/core/src/genesis.rs
index eda2745b1..887f058ac 100644
--- a/core/src/genesis.rs
+++ b/core/src/genesis.rs
@@ -111,11 +111,11 @@ pub fn genesis_testnet4() -> core::Block {
 	core::Block::with_header(core::BlockHeader {
 		height: 0,
 		previous: core::hash::Hash([0xff; 32]),
-		timestamp: Utc.ymd(2018, 10, 15).and_hms(12, 0, 0),
+		timestamp: Utc.ymd(2018, 10, 16).and_hms(9, 0, 0),
 		pow: ProofOfWork {
 			total_difficulty: Difficulty::from_num(global::initial_block_difficulty()),
 			scaling_difficulty: 1,
-			nonce: 4956988373127691,
+			nonce: 4956988373127692,
 			proof: Proof::new(vec![
 				0xa420dc, 0xc8ffee, 0x10e433e, 0x1de9428, 0x2ed4cea, 0x52d907b, 0x5af0e3f,
 				0x6b8fcae, 0x8319b53, 0x845ca8c, 0x8d2a13e, 0x8d6e4cc, 0x9349e8d, 0xa7a33c5,
diff --git a/core/tests/consensus.rs b/core/tests/consensus.rs
index 51781c3c8..5895fb18d 100644
--- a/core/tests/consensus.rs
+++ b/core/tests/consensus.rs
@@ -408,17 +408,17 @@ fn next_target_adjustment() {
 	let diff_one = Difficulty::one();
 	assert_eq!(
 		next_difficulty(1, vec![HeaderInfo::from_ts_diff(cur_time, diff_one)]),
-		HeaderInfo::from_diff_scaling(Difficulty::one(), 4),
+		HeaderInfo::from_diff_scaling(Difficulty::one(), 2),
 	);
 	assert_eq!(
 		next_difficulty(1, vec![HeaderInfo::new(cur_time, diff_one, 10, true)]),
-		HeaderInfo::from_diff_scaling(Difficulty::one(), 4),
+		HeaderInfo::from_diff_scaling(Difficulty::one(), 2),
 	);
 
 	let mut hi = HeaderInfo::from_diff_scaling(diff_one, 1);
 	assert_eq!(
 		next_difficulty(1, repeat(60, hi.clone(), DIFFICULTY_ADJUST_WINDOW, None)),
-		HeaderInfo::from_diff_scaling(Difficulty::one(), 4),
+		HeaderInfo::from_diff_scaling(Difficulty::one(), 2),
 	);
 	hi.is_secondary = true;
 	assert_eq!(
@@ -520,7 +520,7 @@ fn secondary_pow_scale() {
 	// becomes easier to find a high difficulty block
 	assert_eq!(
 		secondary_pow_scaling(1, &(0..window).map(|_| hi.clone()).collect()),
-		400
+		200
 	);
 	// all secondary on 90%, factor should lose 10%
 	hi.is_secondary = true;
@@ -531,7 +531,7 @@ fn secondary_pow_scale() {
 	// all secondary on 1%, should be divided by 4 (max adjustment)
 	assert_eq!(
 		secondary_pow_scaling(890_000, &(0..window).map(|_| hi.clone()).collect()),
-		25
+		50
 	);
 	// same as above, testing lowest bound
 	let mut low_hi = HeaderInfo::from_diff_scaling(Difficulty::from_num(10), 3);
@@ -572,7 +572,7 @@ fn secondary_pow_scale() {
 				.chain((0..(window * 4 / 10)).map(|_| hi.clone()))
 				.collect()
 		),
-		112
+		100
 	);
 }
 
diff --git a/p2p/src/msg.rs b/p2p/src/msg.rs
index e09f5cbda..21068c893 100644
--- a/p2p/src/msg.rs
+++ b/p2p/src/msg.rs
@@ -35,7 +35,7 @@ pub const PROTOCOL_VERSION: u32 = 1;
 pub const USER_AGENT: &'static str = concat!("MW/Grin ", env!("CARGO_PKG_VERSION"));
 
 /// Magic number expected in the header of every message
-const MAGIC: [u8; 2] = [0x1e, 0xc5];
+const MAGIC: [u8; 2] = [0x47, 0x31];
 
 /// Size in bytes of a message header
 pub const HEADER_LEN: u64 = 11;