diff --git a/tests/core/pyspec/eth2spec/test/electra/block_processing/test_process_withdrawal_request.py b/tests/core/pyspec/eth2spec/test/electra/block_processing/test_process_withdrawal_request.py
index e3ebcae7e..39626ee05 100644
--- a/tests/core/pyspec/eth2spec/test/electra/block_processing/test_process_withdrawal_request.py
+++ b/tests/core/pyspec/eth2spec/test/electra/block_processing/test_process_withdrawal_request.py
@@ -124,7 +124,7 @@ def test_basic_withdrawal_request_with_full_partial_withdrawal_queue(spec, state
     )
 
 
-# Invalid tests
+# Tests that should fail
 
 
 @with_electra_and_later
@@ -237,6 +237,31 @@ def test_activation_epoch_less_than_shard_committee_period(spec, state):
     )
 
 
+@with_electra_and_later
+@spec_state_test
+def test_unknown_pubkey(spec, state):
+    rng = random.Random(1344)
+    # move state forward SHARD_COMMITTEE_PERIOD epochs to allow for exit
+    state.slot += spec.config.SHARD_COMMITTEE_PERIOD * spec.SLOTS_PER_EPOCH
+
+    current_epoch = spec.get_current_epoch(state)
+    validator_index = rng.choice(spec.get_active_validator_indices(state, current_epoch))
+    address = b"\x22" * 20
+    pubkey = spec.BLSPubkey(b"\x23" * 48)
+    set_eth1_withdrawal_credential_with_balance(
+        spec, state, validator_index, address=address
+    )
+    withdrawal_request = spec.WithdrawalRequest(
+        source_address=address,
+        validator_pubkey=pubkey,
+        amount=spec.FULL_EXIT_REQUEST_AMOUNT,
+    )
+
+    yield from run_withdrawal_request_processing(
+        spec, state, withdrawal_request, success=False
+    )
+
+
 # Partial withdrawals tests
 
 @with_electra_and_later
@@ -896,10 +921,6 @@ def run_withdrawal_request_processing(
     If ``valid == False``, run expecting ``AssertionError``
     If ``success == False``, it doesn't initiate exit successfully
     """
-    validator_index = get_validator_index_by_pubkey(
-        state, withdrawal_request.validator_pubkey
-    )
-
     yield "pre", state
     yield "withdrawal_request", withdrawal_request
 
@@ -912,14 +933,7 @@ def run_withdrawal_request_processing(
         yield "post", None
         return
 
-    pre_exit_epoch = state.validators[validator_index].exit_epoch
-    pre_pending_partial_withdrawals = state.pending_partial_withdrawals.copy()
-    pre_balance = state.balances[validator_index]
-    pre_effective_balance = state.validators[validator_index].effective_balance
     pre_state = state.copy()
-    expected_amount_to_withdraw = compute_amount_to_withdraw(
-        spec, state, validator_index, withdrawal_request.amount
-    )
 
     spec.process_withdrawal_request(
         state, withdrawal_request
@@ -931,6 +945,13 @@ def run_withdrawal_request_processing(
         # No-op
         assert pre_state == state
     else:
+        validator_index = get_validator_index_by_pubkey(
+            state, withdrawal_request.validator_pubkey
+        )
+        pre_exit_epoch = pre_state.validators[validator_index].exit_epoch
+        pre_pending_partial_withdrawals = pre_state.pending_partial_withdrawals.copy()
+        pre_balance = pre_state.balances[validator_index]
+        pre_effective_balance = pre_state.validators[validator_index].effective_balance
         assert state.balances[validator_index] == pre_balance
         assert (
             state.validators[validator_index].effective_balance == pre_effective_balance
@@ -943,6 +964,9 @@ def run_withdrawal_request_processing(
             assert state.pending_partial_withdrawals == pre_pending_partial_withdrawals
         # Partial withdrawal request
         else:
+            expected_amount_to_withdraw = compute_amount_to_withdraw(
+                spec, pre_state, validator_index, withdrawal_request.amount
+            )
             assert state.validators[validator_index].exit_epoch == spec.FAR_FUTURE_EPOCH
             expected_withdrawable_epoch = (
                 state.earliest_exit_epoch