diff --git a/base_layer/core/Cargo.toml b/base_layer/core/Cargo.toml
index 80b325dd63..6a71fe47d2 100644
--- a/base_layer/core/Cargo.toml
+++ b/base_layer/core/Cargo.toml
@@ -49,7 +49,7 @@ arrayref = "0.3.5"
 bincode = "1.1.4"
 log = "0.4"
 blake2 = "^0.8.0"
-bigint = "^4.4.1"
+uint = { version = "0.8", default-features = false }
 ttl_cache = "0.5.1"
 tokio = { version="^0.2", features = ["blocking", "time"] }
 futures = {version = "^0.3.1", features = ["async-await"] }
diff --git a/base_layer/core/src/lib.rs b/base_layer/core/src/lib.rs
index 00fa6dd421..dab8c94b3a 100644
--- a/base_layer/core/src/lib.rs
+++ b/base_layer/core/src/lib.rs
@@ -60,3 +60,8 @@ pub mod transactions;
 // Re-export the crypto crate to make exposing traits etc easier for clients of this crate
 pub use crypto::tari_utilities;
 pub use tari_crypto as crypto;
+
+uint::construct_uint! {
+    /// 256-bit unsigned integer.
+    pub(crate) struct U256(4);
+}
diff --git a/base_layer/core/src/proof_of_work/blake_pow.rs b/base_layer/core/src/proof_of_work/blake_pow.rs
index bc987bfd08..b950a7350c 100644
--- a/base_layer/core/src/proof_of_work/blake_pow.rs
+++ b/base_layer/core/src/proof_of_work/blake_pow.rs
@@ -20,8 +20,7 @@
 // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 // USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-use crate::{blocks::BlockHeader, proof_of_work::Difficulty};
-use bigint::uint::U256;
+use crate::{blocks::BlockHeader, proof_of_work::Difficulty, U256};
 use blake2::Blake2b;
 use digest::Digest;
 use tari_crypto::{common::Blake256, tari_utilities::Hashable};
@@ -43,7 +42,7 @@ pub fn blake_difficulty_with_hash(header: &BlockHeader) -> (Difficulty, Vec<u8>)
     let hash = Blake256::digest(&hash).to_vec();
     let scalar = U256::from_big_endian(&hash); // Big endian so the hash has leading zeroes
     let result = MAX_TARGET / scalar;
-    let difficulty = u64::from(result).into();
+    let difficulty = result.low_u64().into();
     (difficulty, hash)
 }
 
diff --git a/base_layer/core/src/proof_of_work/monero_rx.rs b/base_layer/core/src/proof_of_work/monero_rx.rs
index c9ced9d777..6d4fe86585 100644
--- a/base_layer/core/src/proof_of_work/monero_rx.rs
+++ b/base_layer/core/src/proof_of_work/monero_rx.rs
@@ -23,8 +23,8 @@
 use crate::{
     blocks::BlockHeader,
     proof_of_work::{monero_rx::MergeMineError::HashingError, Difficulty},
+    U256,
 };
-use bigint::uint::U256;
 use derive_error::Error;
 use monero::blockdata::{block::BlockHeader as MoneroBlockHeader, Transaction as MoneroTransaction};
 #[cfg(feature = "monero_merge_mining")]
@@ -94,7 +94,7 @@ fn monero_difficulty_calculation(header: &BlockHeader) -> Result<Difficulty, Mer
         let hash = vm.calculate_hash(&input)?;
         let scalar = U256::from_big_endian(&hash); // Big endian so the hash has leading zeroes
         let result = MAX_TARGET / scalar;
-        let difficulty = u64::from(result).into();
+        let difficulty = result.low_u64().into();
         Ok(difficulty)
     }
     #[cfg(not(feature = "monero_merge_mining"))]