diff --git a/test_libs/pyspec/tests/epoch_processing/test_process_registry_updates.py b/test_libs/pyspec/tests/epoch_processing/test_process_registry_updates.py
new file mode 100644
index 000000000..9bc70335b
--- /dev/null
+++ b/test_libs/pyspec/tests/epoch_processing/test_process_registry_updates.py
@@ -0,0 +1,35 @@
+from copy import deepcopy
+
+import eth2spec.phase0.spec as spec
+
+from eth2spec.phase0.spec import (
+    get_current_epoch,
+    is_active_validator,
+)
+from tests.helpers import (
+    next_epoch,
+)
+
+
+def test_activation(state):
+    # Mock a new deposit
+    index = 0
+    state.validator_registry[index].activation_eligibility_epoch = spec.FAR_FUTURE_EPOCH
+    state.validator_registry[index].activation_epoch = spec.FAR_FUTURE_EPOCH
+    state.validator_registry[index].effective_balance = spec.MAX_EFFECTIVE_BALANCE
+
+    assert not is_active_validator(state.validator_registry[index], get_current_epoch(state))
+
+    pre_state = deepcopy(state)
+
+    for _ in range(spec.ACTIVATION_EXIT_DELAY + 1):
+        next_epoch(state)
+
+    assert state.validator_registry[index].activation_eligibility_epoch != spec.FAR_FUTURE_EPOCH
+    assert state.validator_registry[index].activation_epoch != spec.FAR_FUTURE_EPOCH
+    assert is_active_validator(
+        state.validator_registry[index],
+        get_current_epoch(state),
+    )
+
+    return pre_state, state