diff --git a/tests/core/pyspec/eth2spec/test/helpers/multi_operations.py b/tests/core/pyspec/eth2spec/test/helpers/multi_operations.py
index c0a58dbca..075b03aa0 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/multi_operations.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/multi_operations.py
@@ -213,7 +213,7 @@ def run_test_full_random_operations(spec, state, rng=Random(2080)):
     yield 'post', state
 
 
-def get_random_sync_aggregate(spec, state, fraction_participated=1.0, rng=Random(2099)):
+def get_random_sync_aggregate(spec, state, slot, fraction_participated=1.0, rng=Random(2099)):
     committee_indices = compute_committee_indices(spec, state, state.current_sync_committee)
     participant_count = int(len(committee_indices) * fraction_participated)
     participant_indices = rng.sample(range(len(committee_indices)), participant_count)
@@ -224,7 +224,7 @@ def get_random_sync_aggregate(spec, state, fraction_participated=1.0, rng=Random
     signature = compute_aggregate_sync_committee_signature(
         spec,
         state,
-        state.slot - 1,
+        slot,
         participants,
     )
     return spec.SyncAggregate(
diff --git a/tests/core/pyspec/eth2spec/test/utils/random.py b/tests/core/pyspec/eth2spec/test/utils/random.py
index 2f727e749..d17a3a9b2 100644
--- a/tests/core/pyspec/eth2spec/test/utils/random.py
+++ b/tests/core/pyspec/eth2spec/test/utils/random.py
@@ -123,7 +123,12 @@ def random_block_altair(spec, state, signed_blocks):
     block = random_block(spec, state, signed_blocks)
     fraction_missed = len(signed_blocks) / SYNC_AGGREGATE_PARTICIPATION_BUCKETS
     fraction_participated = 1.0 - fraction_missed
-    block.body.sync_aggregate = get_random_sync_aggregate(spec, state, fraction_participated=fraction_participated)
+    block.body.sync_aggregate = get_random_sync_aggregate(
+        spec,
+        state,
+        block.slot - 1,
+        fraction_participated=fraction_participated,
+    )
     return block