diff --git a/hare4/hare.go b/hare4/hare.go
index 0e01825017..6fe885a758 100644
--- a/hare4/hare.go
+++ b/hare4/hare.go
@@ -9,6 +9,7 @@ import (
 	"math"
 	"slices"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/jonboulle/clockwork"
@@ -199,11 +200,12 @@ func New(
 	proposals *store.Store,
 	verifier verifier,
 	oracle oracle,
-	sync system.SyncStateProvider,
+	syncProv system.SyncStateProvider,
 	patrol *layerpatrol.LayerPatrol,
 	host server.Host,
 	opts ...Opt,
 ) *Hare {
+	condMtx := &sync.Mutex{}
 	ctx, cancel := context.WithCancel(context.Background())
 	hr := &Hare{
 		ctx:          ctx,
@@ -213,6 +215,7 @@ func New(
 		signers:      make(map[string]*signing.EdSigner),
 		sessions:     make(map[types.LayerID]*protocol),
 		messageCache: make(map[types.Hash32]Message),
+		cond:         sync.NewCond(condMtx),
 
 		config:    DefaultConfig(),
 		log:       zap.NewNop(),
@@ -229,7 +232,7 @@ func New(
 			oracle: oracle,
 			config: DefaultConfig(),
 		},
-		sync:   sync,
+		sync:   syncProv,
 		patrol: patrol,
 		tracer: noopTracer{},
 	}
@@ -255,6 +258,8 @@ type Hare struct {
 	sessions     map[types.LayerID]*protocol
 	messageCache map[types.Hash32]Message
 
+	cond *sync.Cond
+
 	// options
 	config    Config
 	log       *zap.Logger
@@ -503,10 +508,45 @@ func (h *Hare) Handler(ctx context.Context, peer p2p.Peer, buf []byte) error {
 		switch {
 		case errors.Is(err, errCannotMatchProposals):
 			h.log.Info("preround message but couldn't reconstruct", zap.Int("nr compacts", len(compacts)), zap.Inline(msg))
+			grindOk := atomic.Bool{}
+			grindFail := atomic.Bool{}
+			ownSucceeded := atomic.Bool{}
+			go func() {
+				h.cond.L.Lock()
+				for i := 0; i < 5; i++ {
+					h.cond.Wait()
+					if ownSucceeded.Load() {
+						break
+					}
+					err := h.reconstructProposals(ctx, peer, msgId, msg)
+					if err != nil {
+						h.log.Error("hare4 grind reconstruct proposals error", zap.Error(err))
+					} else {
+						grindOk.Store(true)
+						break
+					}
+				}
+				h.cond.L.Unlock()
+				grindFail.Store(true)
+			}()
+			start := time.Now()
 			msg.Value.Proposals, err = h.fetchFull(ctx, peer, msgId)
 			if err != nil {
+				for !grindFail.Load() {
+					if grindOk.Load() {
+						goto SORT
+					}
+					time.Sleep(50 * time.Millisecond)
+					if time.Since(start) > 2*time.Second {
+						break
+					}
+				}
+
 				return fmt.Errorf("fetch full: %w", err)
 			}
+			ownSucceeded.Store(true)
+			h.cond.Broadcast()
+		SORT:
 			slices.SortFunc(msg.Value.Proposals, func(i, j types.ProposalID) int { return bytes.Compare(i[:], j[:]) })
 			msg.Value.CompactProposals = []types.CompactProposalID{}
 			fetched = true
diff --git a/hare4/hare_test.go b/hare4/hare_test.go
index abc9005b51..716daa2f48 100644
--- a/hare4/hare_test.go
+++ b/hare4/hare_test.go
@@ -224,6 +224,7 @@ func (n *node) withPublisher() *node {
 
 func (n *node) withStreamRequester() *node {
 	n.mockStreamRequester = hmock.NewMockstreamRequester(n.ctrl)
+	n.mockStreamRequester.EXPECT().Run(gomock.Any()).Return(nil).AnyTimes()
 	return n
 }
 
@@ -599,6 +600,7 @@ func (cl *lockstepCluster) drainInteractiveMessages() {
 				case <-n.tracer.compactReq:
 				case <-n.tracer.compactResp:
 				case <-done:
+					return
 				}
 			}
 		}()
diff --git a/hare4/protocol.go b/hare4/protocol.go
index d6d76d8268..34b58f1d86 100644
--- a/hare4/protocol.go
+++ b/hare4/protocol.go
@@ -114,7 +114,6 @@ func (p *protocol) OnInitial(proposals []types.ProposalID) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 	p.initial = proposals
-	fmt.Println("protocol on initial proposals", len(p.initial))
 }
 
 func (p *protocol) OnInput(msg *input) (bool, *wire.HareProof) {