diff --git a/programs/bpf_loader/src/lib.rs b/programs/bpf_loader/src/lib.rs
index 815cd103fb..3eed89919e 100644
--- a/programs/bpf_loader/src/lib.rs
+++ b/programs/bpf_loader/src/lib.rs
@@ -421,7 +421,9 @@ fn process_loader_upgradeable_instruction(
             program.try_account_ref_mut()?.executable = true;
 
             // Drain the Buffer account back to the payer
-            payer.try_account_ref_mut()?.lamports += buffer.lamports()?;
+            payer
+                .try_account_ref_mut()?
+                .checked_add_lamports(buffer.lamports()?)?;
             buffer.try_account_ref_mut()?.lamports = 0;
 
             ic_logger_msg!(logger, "Deployed program {:?}", program.unsigned_key());
@@ -547,9 +549,10 @@ fn process_loader_upgradeable_instruction(
 
             // Fund ProgramData to rent-exemption, spill the rest
 
-            spill.try_account_ref_mut()?.lamports += (programdata.lamports()?
-                + buffer.lamports()?)
-            .saturating_sub(programdata_balance_required);
+            spill.try_account_ref_mut()?.checked_add_lamports(
+                (programdata.lamports()? + buffer.lamports()?)
+                    .saturating_sub(programdata_balance_required),
+            )?;
             buffer.try_account_ref_mut()?.lamports = 0;
             programdata.try_account_ref_mut()?.lamports = programdata_balance_required;
 
@@ -640,7 +643,9 @@ fn process_loader_upgradeable_instruction(
                     return Err(InstructionError::MissingRequiredSignature);
                 }
 
-                recipient_account.try_account_ref_mut()?.lamports += close_account.lamports()?;
+                recipient_account
+                    .try_account_ref_mut()?
+                    .checked_add_lamports(close_account.lamports()?)?;
                 close_account.try_account_ref_mut()?.lamports = 0;
                 for elt in close_account.try_account_ref_mut()?.data_as_mut_slice() {
                     *elt = 0;
diff --git a/programs/budget/src/budget_processor.rs b/programs/budget/src/budget_processor.rs
index 85d5ba9332..730469858a 100644
--- a/programs/budget/src/budget_processor.rs
+++ b/programs/budget/src/budget_processor.rs
@@ -49,7 +49,9 @@ fn apply_signature(
         }
         budget_state.pending_budget = None;
         contract_keyed_account.try_account_ref_mut()?.lamports -= payment.lamports;
-        to_keyed_account.try_account_ref_mut()?.lamports += payment.lamports;
+        to_keyed_account
+            .try_account_ref_mut()?
+            .checked_add_lamports(payment.lamports)?;
     }
     Ok(())
 }
@@ -80,7 +82,9 @@ fn apply_timestamp(
         }
         budget_state.pending_budget = None;
         contract_keyed_account.try_account_ref_mut()?.lamports -= payment.lamports;
-        to_keyed_account.try_account_ref_mut()?.lamports += payment.lamports;
+        to_keyed_account
+            .try_account_ref_mut()?
+            .checked_add_lamports(payment.lamports)?;
     }
     Ok(())
 }
@@ -111,7 +115,9 @@ fn apply_account_data(
         }
         budget_state.pending_budget = None;
         contract_keyed_account.try_account_ref_mut()?.lamports -= payment.lamports;
-        to_keyed_account.try_account_ref_mut()?.lamports += payment.lamports;
+        to_keyed_account
+            .try_account_ref_mut()?
+            .checked_add_lamports(payment.lamports)?;
     }
     Ok(())
 }
@@ -135,7 +141,9 @@ pub fn process_instruction(
                 let to_keyed_account = contract_keyed_account;
                 let contract_keyed_account = keyed_account_at_index(keyed_accounts, 1)?;
                 contract_keyed_account.try_account_ref_mut()?.lamports = 0;
-                to_keyed_account.try_account_ref_mut()?.lamports += payment.lamports;
+                to_keyed_account
+                    .try_account_ref_mut()?
+                    .checked_add_lamports(payment.lamports)?;
                 return Ok(());
             }
             let existing =
diff --git a/programs/stake/src/stake_state.rs b/programs/stake/src/stake_state.rs
index 25c632a36a..021ac1b20f 100644
--- a/programs/stake/src/stake_state.rs
+++ b/programs/stake/src/stake_state.rs
@@ -10,7 +10,7 @@ use crate::{
 };
 use serde_derive::{Deserialize, Serialize};
 use solana_sdk::{
-    account::{AccountSharedData, ReadableAccount},
+    account::{AccountSharedData, ReadableAccount, WritableAccount},
     account_utils::{State, StateMut},
     clock::{Clock, Epoch, UnixTimestamp},
     ic_msg,
@@ -1155,7 +1155,9 @@ impl<'a> StakeAccount for KeyedAccount<'a> {
                 self.set_state(&StakeState::Uninitialized)?;
             }
 
-            split.try_account_ref_mut()?.lamports += lamports;
+            split
+                .try_account_ref_mut()?
+                .checked_add_lamports(lamports)?;
             self.try_account_ref_mut()?.lamports -= lamports;
             Ok(())
         } else {
@@ -1203,7 +1205,7 @@ impl<'a> StakeAccount for KeyedAccount<'a> {
         // Drain the source stake account
         let lamports = source_account.lamports()?;
         source_account.try_account_ref_mut()?.lamports -= lamports;
-        self.try_account_ref_mut()?.lamports += lamports;
+        self.try_account_ref_mut()?.checked_add_lamports(lamports)?;
         Ok(())
     }
 
@@ -1284,7 +1286,7 @@ impl<'a> StakeAccount for KeyedAccount<'a> {
         }
 
         self.try_account_ref_mut()?.lamports -= lamports;
-        to.try_account_ref_mut()?.lamports += lamports;
+        to.try_account_ref_mut()?.checked_add_lamports(lamports)?;
         Ok(())
     }
 }
@@ -1486,8 +1488,8 @@ pub fn redeem_rewards(
             inflation_point_calc_tracer,
             fix_stake_deactivate,
         ) {
-            stake_account.lamports += stakers_reward;
-            vote_account.lamports += voters_reward;
+            stake_account.checked_add_lamports(stakers_reward)?;
+            vote_account.checked_add_lamports(voters_reward)?;
 
             stake_account.set_state(&StakeState::Stake(meta, stake))?;
 
@@ -3171,7 +3173,7 @@ mod tests {
         );
 
         // simulate rewards
-        stake_account.borrow_mut().lamports += 10;
+        stake_account.borrow_mut().checked_add_lamports(10).unwrap();
         // withdrawal before deactivate works for rewards amount
         let stake_keyed_account = KeyedAccount::new(&stake_pubkey, true, &stake_account);
         let to_keyed_account = KeyedAccount::new(&to, false, &to_account);
@@ -3188,7 +3190,7 @@ mod tests {
         );
 
         // simulate rewards
-        stake_account.borrow_mut().lamports += 10;
+        stake_account.borrow_mut().checked_add_lamports(10).unwrap();
         // withdrawal of rewards fails if not in excess of stake
         let stake_keyed_account = KeyedAccount::new(&stake_pubkey, true, &stake_account);
         let to_keyed_account = KeyedAccount::new(&to, false, &to_account);
@@ -5964,7 +5966,11 @@ mod tests {
         stake_keyed_account.deactivate(&clock, &signers).unwrap();
 
         // Out of band deposit
-        stake_keyed_account.try_account_ref_mut().unwrap().lamports += withdraw_lamports;
+        stake_keyed_account
+            .try_account_ref_mut()
+            .unwrap()
+            .checked_add_lamports(withdraw_lamports)
+            .unwrap();
 
         clock.epoch += 1;
         stake_keyed_account