diff --git a/test_libs/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_rewards_and_penalties.py b/test_libs/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_rewards_and_penalties.py
index 857ad8bb0..09f4b9eb0 100644
--- a/test_libs/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_rewards_and_penalties.py
+++ b/test_libs/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_rewards_and_penalties.py
@@ -170,3 +170,42 @@ def test_duplicate_attestation(spec, state):
     for index in participants:
         assert state.balances[index] < single_state.balances[index]
         assert single_state.balances[index] == dup_state.balances[index]
+
+
+@with_all_phases
+@spec_state_test
+# Case when some eligible attestations are slashed. Modifies attesting_balance and consequently rewards/penalties.
+def test_attestations_some_slashed(spec, state):
+    attestations = []
+    for slot in range(spec.SLOTS_PER_EPOCH + spec.MIN_ATTESTATION_INCLUSION_DELAY):
+        # create an attestation for each slot in epoch
+        if slot < spec.SLOTS_PER_EPOCH:
+            attestation = get_valid_attestation(spec, state, signed=True)
+            attestations.append(attestation)
+        # fill each created slot in state after inclusion delay
+        if slot - spec.MIN_ATTESTATION_INCLUSION_DELAY >= 0:
+            include_att = attestations[slot - spec.MIN_ATTESTATION_INCLUSION_DELAY]
+            add_attestations_to_state(spec, state, [include_att], state.slot)
+        next_slot(spec, state)
+
+    attesting_indices_before_slashings = spec.get_unslashed_attesting_indices(state, attestations)
+
+    # Slash maximum amount of validators allowed per epoch.
+    for i in range(spec.MIN_PER_EPOCH_CHURN_LIMIT):
+        spec.slash_validator(state, list(attesting_indices_before_slashings)[i])
+
+    assert spec.compute_epoch_of_slot(state.slot) == spec.GENESIS_EPOCH + 1
+    assert len(state.previous_epoch_attestations) == spec.SLOTS_PER_EPOCH
+
+    pre_state = deepcopy(state)
+
+    yield from run_process_rewards_and_penalties(spec, state)
+
+    attesting_indices = spec.get_unslashed_attesting_indices(state, attestations)
+    assert len(attesting_indices) > 0
+    assert len(attesting_indices_before_slashings) - len(attesting_indices) == spec.MIN_PER_EPOCH_CHURN_LIMIT
+    for index in range(len(pre_state.validators)):
+        if index in attesting_indices:
+            assert state.balances[index] > pre_state.balances[index]
+        else:
+            assert state.balances[index] < pre_state.balances[index]