diff --git a/test_generators/epoch_processing/main.py b/test_generators/epoch_processing/main.py
index 530f9485d..14df53aba 100644
--- a/test_generators/epoch_processing/main.py
+++ b/test_generators/epoch_processing/main.py
@@ -32,8 +32,7 @@ def create_suite(transition_name: str, config_name: str, get_cases: Callable[[],
 if __name__ == "__main__":
     gen_runner.run_generator("epoch_processing", [
         create_suite('crosslinks',       'minimal', lambda: generate_from_tests(test_process_crosslinks)),
-        # To be updated to support mainnet config.
-        # create_suite('crosslinks',       'mainnet', lambda: generate_from_tests(test_process_crosslinks)),
+        create_suite('crosslinks',       'mainnet', lambda: generate_from_tests(test_process_crosslinks)),
         create_suite('registry_updates', 'minimal', lambda: generate_from_tests(test_process_registry_updates)),
         create_suite('registry_updates', 'mainnet', lambda: generate_from_tests(test_process_registry_updates)),
     ])
diff --git a/test_libs/gen_helpers/gen_from_tests/gen.py b/test_libs/gen_helpers/gen_from_tests/gen.py
index 1b9d60f7e..d954e0485 100644
--- a/test_libs/gen_helpers/gen_from_tests/gen.py
+++ b/test_libs/gen_helpers/gen_from_tests/gen.py
@@ -16,7 +16,10 @@ def generate_from_tests(src, bls_active=True):
     for name in fn_names:
         tfn = getattr(src, name)
         try:
-            out.append(tfn(generator_mode=True, bls_active=bls_active))
+            test_case = tfn(generator_mode=True, bls_active=bls_active))
+            # If no test case data is returned, the test is ignored.
+            if test_case is not None:
+                out.append(test_case)
         except AssertionError:
             print("ERROR: failed to generate vector from test: %s (src: %s)" % (name, src.__name__))
     return out
diff --git a/test_libs/pyspec/eth2spec/test/epoch_processing/test_process_crosslinks.py b/test_libs/pyspec/eth2spec/test/epoch_processing/test_process_crosslinks.py
index 4783c11d1..58c7b669f 100644
--- a/test_libs/pyspec/eth2spec/test/epoch_processing/test_process_crosslinks.py
+++ b/test_libs/pyspec/eth2spec/test/epoch_processing/test_process_crosslinks.py
@@ -104,6 +104,10 @@ def test_single_crosslink_update_from_previous_epoch(state):
 
 @spec_state_test
 def test_double_late_crosslink(state):
+    if spec.SLOTS_PER_EPOCH < spec.SHARD_COUNT:
+        print("warning: ignoring test, test-assumptions are incompatible with configuration")
+        return
+
     next_epoch(state)
     state.slot += 4
 
diff --git a/test_libs/pyspec/eth2spec/test/utils.py b/test_libs/pyspec/eth2spec/test/utils.py
index c1d424109..02bc9a1e6 100644
--- a/test_libs/pyspec/eth2spec/test/utils.py
+++ b/test_libs/pyspec/eth2spec/test/utils.py
@@ -19,8 +19,10 @@ def spectest(description: str = None):
                 else:
                     # description can be explicit
                     out['description'] = description
+                has_contents = False
                 # put all generated data into a dict.
                 for data in fn(*args, **kw):
+                    has_contents = True
                     # If there is a type argument, encode it as that type.
                     if len(data) == 3:
                         (key, value, typ) = data
@@ -32,11 +34,15 @@ def spectest(description: str = None):
                             out[key] = encode(value, value.__class__)
                         else:
                             out[key] = value
-                return out
+                if has_contents:
+                    return out
+                else:
+                    return None
             else:
                 # just complete the function, ignore all yielded data, we are not using it
                 for _ in fn(*args, **kw):
                     continue
+                return None
         return entry
     return runner