diff --git a/tests/core/pyspec/eth2spec/test/helpers/attestations.py b/tests/core/pyspec/eth2spec/test/helpers/attestations.py
index 40179150f..fe42a3949 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/attestations.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/attestations.py
@@ -219,6 +219,26 @@ def add_attestations_to_state(spec, state, attestations, slot):
         spec.process_attestation(state, attestation)
 
 
+def _get_valid_attestation_at_slot(state, spec, slot_to_attest, participation_fn=None, on_time=True):
+    committees_per_slot = spec.get_committee_count_per_slot(state, spec.compute_epoch_at_slot(slot_to_attest))
+    for index in range(committees_per_slot):
+        def participants_filter(comm):
+            if participation_fn is None:
+                return comm
+            else:
+                return participation_fn(state.slot, index, comm)
+        # if spec.fork == SHARDING:  TODO: add shard data to attestation, include shard headers in block
+        yield get_valid_attestation(
+            spec,
+            state,
+            slot_to_attest,
+            index=index,
+            signed=True,
+            on_time=on_time,
+            filter_participant_set=participants_filter
+        )
+
+
 def next_slots_with_attestations(spec,
                                  state,
                                  slot_count,
@@ -234,42 +254,26 @@ def next_slots_with_attestations(spec,
         block = build_empty_block_for_next_slot(spec, post_state)
         if fill_cur_epoch and post_state.slot >= spec.MIN_ATTESTATION_INCLUSION_DELAY:
             slot_to_attest = post_state.slot - spec.MIN_ATTESTATION_INCLUSION_DELAY + 1
-            committees_per_slot = spec.get_committee_count_per_slot(state, spec.compute_epoch_at_slot(slot_to_attest))
             if slot_to_attest >= spec.compute_start_slot_at_epoch(spec.get_current_epoch(post_state)):
-                for index in range(committees_per_slot):
-                    # if spec.fork == SHARDING:  TODO: add shard data to attestation, include shard headers in block
-                    def participants_filter(comm):
-                        if participation_fn is None:
-                            return comm
-                        else:
-                            return participation_fn(post_state.slot, index, comm)
-
-                    cur_attestation = get_valid_attestation(spec,
-                                                            post_state,
-                                                            slot_to_attest,
-                                                            index=index,
-                                                            signed=True,
-                                                            on_time=True,
-                                                            filter_participant_set=participants_filter)
-                    block.body.attestations.append(cur_attestation)
-
+                attestations = _get_valid_attestation_at_slot(
+                    post_state,
+                    spec,
+                    slot_to_attest,
+                    participation_fn=participation_fn
+                )
+                for attestation in attestations:
+                    block.body.attestations.append(attestation)
         if fill_prev_epoch:
             slot_to_attest = post_state.slot - spec.SLOTS_PER_EPOCH + 1
-            committees_per_slot = spec.get_committee_count_per_slot(state, spec.compute_epoch_at_slot(slot_to_attest))
-            for index in range(committees_per_slot):
-                def participants_filter(comm):
-                    if participation_fn is None:
-                        return comm
-                    else:
-                        return participation_fn(post_state.slot, index, comm)
-                prev_attestation = get_valid_attestation(spec,
-                                                         post_state,
-                                                         slot_to_attest,
-                                                         index=index,
-                                                         signed=True,
-                                                         on_time=False,
-                                                         filter_participant_set=participants_filter)
-                block.body.attestations.append(prev_attestation)
+            attestations = _get_valid_attestation_at_slot(
+                post_state,
+                spec,
+                slot_to_attest,
+                on_time=False,
+                participation_fn=participation_fn
+            )
+            for attestation in attestations:
+                block.body.attestations.append(attestation)
 
         signed_block = state_transition_and_sign_block(spec, post_state, block)
         signed_blocks.append(signed_block)