diff --git a/src/blockchaintree.rs b/src/blockchaintree.rs
index 079d9ff..0add674 100644
--- a/src/blockchaintree.rs
+++ b/src/blockchaintree.rs
@@ -7,12 +7,11 @@ use crate::{
     merkletree,
     static_values::{
         self, AMOUNT_SUMMARY, BLOCKS_PER_EPOCH, BYTE_GAS_PRICE, COINS_PER_CYCLE, GAS_SUMMARY,
-        MAIN_CHAIN_PAYMENT, OLD_AMOUNT_SUMMARY, OLD_GAS_SUMMARY, ROOT_PUBLIC_ADDRESS,
+        OLD_AMOUNT_SUMMARY, OLD_GAS_SUMMARY, ROOT_PUBLIC_ADDRESS,
     },
     tools,
     transaction::Transaction,
     transaction::Transactionable,
-    txpool,
     types::Hash,
 };
 use error_stack::{Report, ResultExt};
diff --git a/src/chain.rs b/src/chain.rs
index 1d0c2ab..6469012 100644
--- a/src/chain.rs
+++ b/src/chain.rs
@@ -162,7 +162,8 @@ impl MainChain {
             .change_context(BlockChainTreeError::Chain(ChainErrorKind::DumpConfig))
             .attach_printable("failed to write height")?;
 
-        file.write_all(self.difficulty.read().as_ref())
+        let difficulty = *self.difficulty.read();
+        file.write_all(&difficulty)
             .await
             .change_context(BlockChainTreeError::Chain(ChainErrorKind::DumpConfig))
             .attach_printable("failed to write difficulty")?;
@@ -540,7 +541,8 @@ impl DerivativeChain {
             .change_context(BlockChainTreeError::Chain(ChainErrorKind::DumpConfig))
             .attach_printable("failed to write height")?;
 
-        file.write_all(self.difficulty.read().as_ref())
+        let difficulty = *self.difficulty.read();
+        file.write_all(&difficulty)
             .await
             .change_context(BlockChainTreeError::Chain(ChainErrorKind::DumpConfig))
             .attach_printable("failed to write difficulty")?;