diff --git a/programs/mango-v4/src/instructions/serum3_cancel_order.rs b/programs/mango-v4/src/instructions/serum3_cancel_order.rs
index 403861c3e..6054fedd6 100644
--- a/programs/mango-v4/src/instructions/serum3_cancel_order.rs
+++ b/programs/mango-v4/src/instructions/serum3_cancel_order.rs
@@ -1,5 +1,5 @@
 use anchor_lang::prelude::*;
-use fixed::types::I80F48;
+
 use serum_dex::instruction::CancelOrderInstructionV2;
 
 use crate::error::*;
@@ -77,7 +77,7 @@ pub fn serum3_cancel_order(
     //
     let before_oo = {
         let open_orders = load_open_orders_ref(ctx.accounts.open_orders.as_ref())?;
-        OpenOrdersSlim::fromOO(&open_orders)
+        OpenOrdersSlim::from_oo(&open_orders)
     };
     let order = serum_dex::instruction::CancelOrderInstructionV2 {
         side: u8::try_from(side).unwrap().try_into().unwrap(),
@@ -87,7 +87,7 @@ pub fn serum3_cancel_order(
 
     {
         let open_orders = load_open_orders_ref(ctx.accounts.open_orders.as_ref())?;
-        let after_oo = OpenOrdersSlim::fromOO(&open_orders);
+        let after_oo = OpenOrdersSlim::from_oo(&open_orders);
         let mut account = ctx.accounts.account.load_mut()?;
         decrease_maybe_loan(
             serum_market.market_index,
diff --git a/programs/mango-v4/src/instructions/serum3_place_order.rs b/programs/mango-v4/src/instructions/serum3_place_order.rs
index c537361ee..d0ef1a354 100644
--- a/programs/mango-v4/src/instructions/serum3_place_order.rs
+++ b/programs/mango-v4/src/instructions/serum3_place_order.rs
@@ -1,4 +1,3 @@
-use crate::accounts_zerocopy::*;
 use crate::error::MangoError;
 
 use crate::serum3_cpi::load_open_orders_ref;
@@ -21,7 +20,7 @@ pub struct OpenOrdersSlim {
     pub native_pc_total: u64,
 }
 impl OpenOrdersSlim {
-    pub fn fromOO(oo: &OpenOrders) -> Self {
+    pub fn from_oo(oo: &OpenOrders) -> Self {
         Self {
             native_coin_free: oo.native_coin_free,
             native_coin_total: oo.native_coin_total,
@@ -224,14 +223,14 @@ pub fn serum3_place_order(
     let before_oo = {
         let oo_ai = &ctx.accounts.open_orders.as_ref();
         let open_orders = load_open_orders_ref(oo_ai)?;
-        OpenOrdersSlim::fromOO(&open_orders)
+        OpenOrdersSlim::from_oo(&open_orders)
     };
     cpi_place_order(ctx.accounts, order)?;
 
     {
         let oo_ai = &ctx.accounts.open_orders.as_ref();
         let open_orders = load_open_orders_ref(oo_ai)?;
-        let after_oo = OpenOrdersSlim::fromOO(&open_orders);
+        let after_oo = OpenOrdersSlim::from_oo(&open_orders);
         let mut account = ctx.accounts.account.load_mut()?;
         inc_maybe_loan(
             serum_market.market_index,
diff --git a/programs/mango-v4/src/instructions/serum3_settle_funds.rs b/programs/mango-v4/src/instructions/serum3_settle_funds.rs
index 09dfeabc9..881ee3088 100644
--- a/programs/mango-v4/src/instructions/serum3_settle_funds.rs
+++ b/programs/mango-v4/src/instructions/serum3_settle_funds.rs
@@ -1,8 +1,8 @@
-use std::{borrow::BorrowMut, cell::RefMut, ops::DerefMut};
+use std::borrow::BorrowMut;
 
 use anchor_lang::prelude::*;
 use anchor_spl::token::{Token, TokenAccount};
-use checked_math as cm;
+
 use fixed::types::I80F48;
 
 use crate::error::*;
@@ -120,8 +120,8 @@ pub fn serum3_settle_funds(ctx: Context<Serum3SettleFunds>) -> Result<()> {
         let open_orders = load_open_orders_ref(ctx.accounts.open_orders.as_ref())?;
         cpi_settle_funds(ctx.accounts)?;
 
-        let after_oo = OpenOrdersSlim::fromOO(&open_orders);
-        let mut account = &mut ctx.accounts.account.load_mut()?;
+        let after_oo = OpenOrdersSlim::from_oo(&open_orders);
+        let account = &mut ctx.accounts.account.load_mut()?;
 
         let mut base_bank = ctx.accounts.base_bank.load_mut()?;
         let mut quote_bank = ctx.accounts.quote_bank.load_mut()?;
@@ -144,8 +144,8 @@ pub fn serum3_settle_funds(ctx: Context<Serum3SettleFunds>) -> Result<()> {
         let after_quote_vault = ctx.accounts.quote_vault.amount;
 
         // Charge the difference in vault balances to the user's account
-        let mut base_bank = ctx.accounts.base_bank.load_mut()?;
-        let mut quote_bank = ctx.accounts.quote_bank.load_mut()?;
+        let base_bank = ctx.accounts.base_bank.load_mut()?;
+        let quote_bank = ctx.accounts.quote_bank.load_mut()?;
         apply_vault_difference(
             ctx.accounts.account.load_mut()?,
             base_bank,
@@ -165,7 +165,7 @@ pub fn charge_maybe_fees(
     market_index: Serum3MarketIndex,
     coin_bank: &mut Bank,
     pc_bank: &mut Bank,
-    mut account: &mut MangoAccount,
+    account: &mut MangoAccount,
     after_oo: &OpenOrdersSlim,
 ) -> Result<()> {
     let serum3_account = account.serum3.find_mut(market_index).unwrap();