diff --git a/chain/stmgr/stmgr.go b/chain/stmgr/stmgr.go
index 7303705cb..0f0717879 100644
--- a/chain/stmgr/stmgr.go
+++ b/chain/stmgr/stmgr.go
@@ -114,7 +114,7 @@ func (sm *StateManager) computeTipSetState(ctx context.Context, blks []*types.Bl
 		return cid.Undef, cid.Undef, xerrors.Errorf("failed to get network actor: %w", err)
 	}
 	reward := vm.MiningReward(netact.Balance)
-	for _, b := range blks {
+	for tsi, b := range blks {
 		netact, err = vmi.StateTree().GetActor(actors.NetworkAddress)
 		if err != nil {
 			return cid.Undef, cid.Undef, xerrors.Errorf("failed to get network actor: %w", err)
@@ -150,7 +150,7 @@ func (sm *StateManager) computeTipSetState(ctx context.Context, blks []*types.Bl
 			return cid.Undef, cid.Undef, xerrors.Errorf("submit election post message for block %s (miner %s) invocation failed: %w", b.Cid(), b.Miner, err)
 		}
 		if ret.ExitCode != 0 {
-			return cid.Undef, cid.Undef, xerrors.Errorf("submit election post invocation returned nonzero exit code: %d (err = %s)", ret.ExitCode, ret.ActorErr)
+			return cid.Undef, cid.Undef, xerrors.Errorf("submit election post invocation returned nonzero exit code: %d (err = %s, block = %s, miner = %s, tsi = %d)", ret.ExitCode, ret.ActorErr, b.Cid(), b.Miner, tsi)
 		}
 	}
 
diff --git a/chain/sync.go b/chain/sync.go
index 9d9e799f1..c632c80a0 100644
--- a/chain/sync.go
+++ b/chain/sync.go
@@ -492,6 +492,15 @@ func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock) err
 	}
 
 	winnerCheck := async.Err(func() error {
+		slashedAt, err := stmgr.GetMinerSlashed(ctx, syncer.sm, baseTs, h.Miner)
+		if err != nil {
+			return xerrors.Errorf("failed to check if block miner was slashed: %w", err)
+		}
+
+		if slashedAt != 0 {
+			return xerrors.Errorf("received block was from miner slashed at height %d", slashedAt)
+		}
+
 		_, tpow, err := stmgr.GetPower(ctx, syncer.sm, baseTs, h.Miner)
 		if err != nil {
 			return xerrors.Errorf("failed getting power: %w", err)