diff --git a/tests/core/pyspec/eth2spec/test/helpers/state.py b/tests/core/pyspec/eth2spec/test/helpers/state.py
index d8fda3754..327bebaf8 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/state.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/state.py
@@ -155,3 +155,15 @@ def ensure_state_has_validators_across_lifecycle(spec, state):
     has_slashed = any(filter(lambda v: v.slashed, state.validators))
 
     return has_pending and has_active and has_exited and has_slashed
+
+
+def has_active_balance_differential(spec, state):
+    """
+    Ensure there is a difference between the total balance of
+    all _active_ validators and _all_ validators.
+    """
+    epoch = spec.get_current_epoch(state)
+    active_indices = spec.get_active_validator_indices(state, epoch)
+    active_balance = spec.get_total_balance(state, set(active_indices))
+    total_balance = spec.get_total_balance(state, set(range(len(state.validators))))
+    return active_balance // spec.EFFECTIVE_BALANCE_INCREMENT != total_balance // spec.EFFECTIVE_BALANCE_INCREMENT
diff --git a/tests/core/pyspec/eth2spec/test/phase0/rewards/test_random.py b/tests/core/pyspec/eth2spec/test/phase0/rewards/test_random.py
index 68a6a3279..44f22270b 100644
--- a/tests/core/pyspec/eth2spec/test/phase0/rewards/test_random.py
+++ b/tests/core/pyspec/eth2spec/test/phase0/rewards/test_random.py
@@ -10,6 +10,7 @@ from eth2spec.test.context import (
 )
 import eth2spec.test.helpers.rewards as rewards_helpers
 from eth2spec.test.helpers.random import randomize_state, patch_state_to_non_leaking
+from eth2spec.test.helpers.state import has_active_balance_differential
 from eth2spec.test.helpers.voluntary_exits import get_unslashed_exited_validators
 
 
@@ -48,6 +49,7 @@ def test_full_random_4(spec, state):
     assert spec.is_in_inactivity_leak(state)
     target_validators = get_unslashed_exited_validators(spec, state)
     assert len(target_validators) != 0
+    assert has_active_balance_differential(spec, state)
     yield from rewards_helpers.run_deltas(spec, state)
 
 
@@ -85,4 +87,5 @@ def test_full_random_without_leak_0(spec, state):
     assert not spec.is_in_inactivity_leak(state)
     target_validators = get_unslashed_exited_validators(spec, state)
     assert len(target_validators) != 0
+    assert has_active_balance_differential(spec, state)
     yield from rewards_helpers.run_deltas(spec, state)