diff --git a/network/src/consensus.rs b/network/src/consensus.rs
index ce7ebfdd..ce3a30be 100644
--- a/network/src/consensus.rs
+++ b/network/src/consensus.rs
@@ -11,7 +11,8 @@ pub const BITCOIN_CASH_FORK_BLOCK: u32 = 478559; // https://blockchair.com/bitco
 pub mod segwit {
 	/// The maximum allowed weight for a block, see BIP 141 (network rule)
 	pub const MAX_BLOCK_WEIGHT: usize = 4_000_000;
-
+	/// The maximum allowed number of signature check operations in a block (network rule)
+	pub const MAX_BLOCK_SIGOPS_COST: usize = 80_000;
 	/// Witness scale factor.
 	pub const WITNESS_SCALE_FACTOR: usize = 4;
 }
@@ -217,6 +218,18 @@ impl ConsensusFork {
 			ConsensusFork::NoFork | ConsensusFork::SegWit2x(_) | ConsensusFork::BitcoinCash(_) => 20_000,
 		}
 	}
+
+	pub fn check_block_sigops(&self, sigops: usize, height: u32, block_size: usize, deployments: &Deployments) -> bool {
+		match *self {
+			// according to REQ-5: max_block_sigops = 20000 * ceil((max(blocksize_bytes, 1000000) / 1000000))
+			ConsensusFork::BitcoinCash(fork_height) if height >= fork_height && block_size > 1_000_000 =>
+				sigops <= 20_000 * (max(block_size, 1_000_000) / 1_000_000),
+			ConsensusFork::NoFork | ConsensusFork::SegWit2x(_) if deployments.is_active("segwit") =>
+				sigops * segwit::WITNESS_SCALE_FACTOR <= segwit::MAX_BLOCK_SIGOPS_COST,
+			ConsensusFork::NoFork | ConsensusFork::SegWit2x(_) | ConsensusFork::BitcoinCash(_) =>
+				sigops <= 20_000,
+		}
+	}
 }
 
 #[cfg(test)]
diff --git a/verification/src/accept_block.rs b/verification/src/accept_block.rs
index fce40386..16b248e8 100644
--- a/verification/src/accept_block.rs
+++ b/verification/src/accept_block.rs
@@ -110,11 +110,14 @@ impl<'a> BlockSerializedSize<'a> {
 
 		let is_segwit_active = self.deployments.is_active("segwit");
 		if is_segwit_active {
-			// TODO: block.vtx.size() * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT
+			if self.block.transactions.len() * segwit::WITNESS_SCALE_FACTOR > segwit::MAX_BLOCK_WEIGHT {
+				return Err(Error::Weight);
+			}
+
 			let size_with_witness = self.block.size_with_witness();
 			let weight = size * (segwit::WITNESS_SCALE_FACTOR - 1) + size_with_witness;
 			if weight > segwit::MAX_BLOCK_WEIGHT {
-				return Err(Error::Weight(weight));
+				return Err(Error::Weight);
 			}
 		}
 		Ok(())
diff --git a/verification/src/error.rs b/verification/src/error.rs
index 16d23dc6..f611dcbb 100644
--- a/verification/src/error.rs
+++ b/verification/src/error.rs
@@ -37,7 +37,7 @@ pub enum Error {
 	/// Block size is invalid
 	Size(usize),
 	/// Block weight is invalid
-	Weight(usize),
+	Weight,
 	/// Block transactions are not final.
 	NonFinalBlock,
 	/// Old version block.