diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index 56a6fd06a..264c6d23b 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -1795,8 +1795,8 @@ def process_transfer(state: BeaconState, transfer: Transfer) -> None:
     """
     Process ``Transfer`` operation.
     """
-    # Verify the amount and fee are not individually too big (for anti-overflow purposes)
-    assert state.balances[transfer.sender] >= max(transfer.amount, transfer.fee)
+    # Verify the balance the covers amount and fee (with overflow protection)
+    assert state.balances[transfer.sender] >= max(transfer.amount + transfer.fee, transfer.amount, transfer.fee)
     # A transfer is valid in only one slot
     assert state.slot == transfer.slot
     # Sender must satisfy at least one of the following conditions in the parenthesis:
diff --git a/test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_transfer.py b/test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_transfer.py
index e9d282b3a..89246cc51 100644
--- a/test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_transfer.py
+++ b/test_libs/pyspec/eth2spec/test/phase_0/block_processing/test_process_transfer.py
@@ -114,7 +114,7 @@ def test_incorrect_slot(spec, state):
 
 @with_all_phases
 @spec_state_test
-def test_insufficient_balance_for_fee(spec, state):
+def test_insufficient_balance_for_fee_result_dust(spec, state):
     sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
     state.balances[sender_index] = spec.MAX_EFFECTIVE_BALANCE
     transfer = get_valid_transfer(spec, state, sender_index=sender_index, amount=0, fee=1, signed=True)
@@ -127,7 +127,20 @@ def test_insufficient_balance_for_fee(spec, state):
 
 @with_all_phases
 @spec_state_test
-def test_insufficient_balance(spec, state):
+def test_insufficient_balance_for_fee_result_full(spec, state):
+    sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
+    transfer = get_valid_transfer(spec, state, sender_index=sender_index,
+                                  amount=0, fee=state.balances[sender_index] + 1, signed=True)
+
+    # un-activate so validator can transfer
+    state.validators[transfer.sender].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+
+    yield from run_transfer_processing(spec, state, transfer, False)
+
+
+@with_all_phases
+@spec_state_test
+def test_insufficient_balance_for_amount_result_dust(spec, state):
     sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
     state.balances[sender_index] = spec.MAX_EFFECTIVE_BALANCE
     transfer = get_valid_transfer(spec, state, sender_index=sender_index, amount=1, fee=0, signed=True)
@@ -138,6 +151,127 @@ def test_insufficient_balance(spec, state):
     yield from run_transfer_processing(spec, state, transfer, False)
 
 
+@with_all_phases
+@spec_state_test
+def test_insufficient_balance_for_amount_result_full(spec, state):
+    sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
+    transfer = get_valid_transfer(spec, state, sender_index=sender_index,
+                                  amount=state.balances[sender_index] + 1, fee=0, signed=True)
+
+    # un-activate so validator can transfer
+    state.validators[transfer.sender].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+
+    yield from run_transfer_processing(spec, state, transfer, False)
+
+
+@with_all_phases
+@spec_state_test
+def test_insufficient_balance_for_combined_result_dust(spec, state):
+    sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
+    # Enough to pay fee without dust, and amount without dust, but not both.
+    state.balances[sender_index] = spec.MIN_DEPOSIT_AMOUNT + 1
+    transfer = get_valid_transfer(spec, state, sender_index=sender_index, amount=1, fee=1, signed=True)
+
+    # un-activate so validator can transfer
+    state.validators[transfer.sender].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+
+    yield from run_transfer_processing(spec, state, transfer, False)
+
+
+@with_all_phases
+@spec_state_test
+def test_insufficient_balance_for_combined_result_full(spec, state):
+    sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
+    # Enough to pay fee fully without dust left, and amount fully without dust left, but not both.
+    state.balances[sender_index] = spec.MIN_DEPOSIT_AMOUNT * 2 + 1
+    transfer = get_valid_transfer(spec, state, sender_index=sender_index,
+                                  amount=spec.MIN_DEPOSIT_AMOUNT + 1,
+                                  fee=spec.MIN_DEPOSIT_AMOUNT + 1, signed=True)
+
+    # un-activate so validator can transfer
+    state.validators[transfer.sender].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+
+    yield from run_transfer_processing(spec, state, transfer, False)
+
+
+@with_all_phases
+@spec_state_test
+def test_insufficient_balance_for_combined_big_amount(spec, state):
+    sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
+    # Enough to pay fee fully without dust left, and amount fully without dust left, but not both.
+    # Try to create a dust balance (off by 1) with combination of fee and amount.
+    state.balances[sender_index] = spec.MIN_DEPOSIT_AMOUNT * 2 + 1
+    transfer = get_valid_transfer(spec, state, sender_index=sender_index,
+                                  amount=spec.MIN_DEPOSIT_AMOUNT + 1, fee=1, signed=True)
+
+    # un-activate so validator can transfer
+    state.validators[transfer.sender].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+
+    yield from run_transfer_processing(spec, state, transfer, False)
+
+
+@with_all_phases
+@spec_state_test
+def test_insufficient_balance_for_combined_big_fee(spec, state):
+    sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
+    # Enough to pay fee fully without dust left, and amount fully without dust left, but not both.
+    # Try to create a dust balance (off by 1) with combination of fee and amount.
+    state.balances[sender_index] = spec.MIN_DEPOSIT_AMOUNT * 2 + 1
+    transfer = get_valid_transfer(spec, state, sender_index=sender_index,
+                                  amount=1, fee=spec.MIN_DEPOSIT_AMOUNT + 1, signed=True)
+
+    # un-activate so validator can transfer
+    state.validators[transfer.sender].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+
+    yield from run_transfer_processing(spec, state, transfer, False)
+
+
+@with_all_phases
+@spec_state_test
+def test_insufficient_balance_off_by_1_fee(spec, state):
+    sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
+    # Enough to pay fee fully without dust left, and amount fully without dust left, but not both.
+    # Try to print money by using the full balance as amount, plus 1 for fee.
+    transfer = get_valid_transfer(spec, state, sender_index=sender_index,
+                                  amount=state.balances[sender_index], fee=1, signed=True)
+
+    # un-activate so validator can transfer
+    state.validators[transfer.sender].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+
+    yield from run_transfer_processing(spec, state, transfer, False)
+
+
+@with_all_phases
+@spec_state_test
+def test_insufficient_balance_off_by_1_amount(spec, state):
+    sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
+    # Enough to pay fee fully without dust left, and amount fully without dust left, but not both.
+    # Try to print money by using the full balance as fee, plus 1 for amount.
+    transfer = get_valid_transfer(spec, state, sender_index=sender_index, amount=1,
+                                  fee=state.balances[sender_index], signed=True)
+
+    # un-activate so validator can transfer
+    state.validators[transfer.sender].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+
+    yield from run_transfer_processing(spec, state, transfer, False)
+
+
+@with_all_phases
+@spec_state_test
+def test_insufficient_balance_duplicate_as_fee_and_amount(spec, state):
+    sender_index = spec.get_active_validator_indices(state, spec.get_current_epoch(state))[-1]
+    # Enough to pay fee fully without dust left, and amount fully without dust left, but not both.
+    # Try to print money by using the full balance, twice.
+    transfer = get_valid_transfer(spec, state, sender_index=sender_index,
+                                  amount=state.balances[sender_index],
+                                  fee=state.balances[sender_index], signed=True)
+
+    # un-activate so validator can transfer
+    state.validators[transfer.sender].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+
+    yield from run_transfer_processing(spec, state, transfer, False)
+
+
 @with_all_phases
 @spec_state_test
 def test_no_dust_sender(spec, state):