diff --git a/test_libs/pyspec/tests/block_processing/test_process_attestation.py b/test_libs/pyspec/tests/block_processing/test_process_attestation.py
index 6851561e9..97eddb902 100644
--- a/test_libs/pyspec/tests/block_processing/test_process_attestation.py
+++ b/test_libs/pyspec/tests/block_processing/test_process_attestation.py
@@ -64,6 +64,22 @@ def test_success_prevous_epoch(state):
     return pre_state, attestation, post_state
 
 
+def test_success_since_max_epochs_per_crosslink(state):
+    for _ in range(spec.MAX_EPOCHS_PER_CROSSLINK + 2):
+        next_epoch(state)
+
+    attestation = get_valid_attestation(state)
+    data = attestation.data
+    assert data.crosslink.end_epoch - data.crosslink.start_epoch == spec.MAX_EPOCHS_PER_CROSSLINK
+
+    for _ in range(spec.MIN_ATTESTATION_INCLUSION_DELAY):
+        next_slot(state)
+
+    pre_state, post_state = run_attestation_processing(state, attestation)
+
+    return pre_state, attestation, post_state
+
+
 def test_before_inclusion_delay(state):
     attestation = get_valid_attestation(state)
     # do not increment slot to allow for inclusion delay
@@ -131,6 +147,32 @@ def test_bad_previous_crosslink(state):
     return pre_state, attestation, post_state
 
 
+def test_bad_crosslink_start_epoch(state):
+    next_epoch(state)
+    attestation = get_valid_attestation(state)
+    for _ in range(spec.MIN_ATTESTATION_INCLUSION_DELAY):
+        next_slot(state)
+
+    attestation.data.crosslink.start_epoch += 1
+
+    pre_state, post_state = run_attestation_processing(state, attestation, False)
+
+    return pre_state, attestation, post_state
+
+
+def test_bad_crosslink_end_epoch(state):
+    next_epoch(state)
+    attestation = get_valid_attestation(state)
+    for _ in range(spec.MIN_ATTESTATION_INCLUSION_DELAY):
+        next_slot(state)
+
+    attestation.data.crosslink.end_epoch += 1
+
+    pre_state, post_state = run_attestation_processing(state, attestation, False)
+
+    return pre_state, attestation, post_state
+
+
 def test_non_empty_custody_bitfield(state):
     attestation = get_valid_attestation(state)
     state.slot += spec.MIN_ATTESTATION_INCLUSION_DELAY