diff --git a/pkg/api/emulation.go b/pkg/api/emulation.go
index 5a2b67c0..f3b422e6 100644
--- a/pkg/api/emulation.go
+++ b/pkg/api/emulation.go
@@ -142,11 +142,7 @@ func (h *Handler) addToMempool(ctx context.Context, bytesBoc []byte, shardAccoun
 	core.Visit(trace, func(node *core.Trace) {
 		accounts[node.Account] = struct{}{}
 	})
-	hash, err := msgCell[0].Hash256()
-	if err != nil {
-		return shardAccount, err
-	}
-	h.mempoolEmulate.traces.Set(hash, trace, cache.WithExpiration(time.Second*time.Duration(ttl)))
+	h.mempoolEmulate.traces.Set(ton.Bits256(message.Hash()), trace, cache.WithExpiration(time.Second*time.Duration(ttl)))
 	var localMessageHashCache = make(map[ton.Bits256]bool)
 	for account := range accounts {
 		if _, ok := h.mempoolEmulateIgnoreAccounts[account]; ok { // the map is filled only once at the start
@@ -166,7 +162,7 @@ func (h *Handler) addToMempool(ctx context.Context, bytesBoc []byte, shardAccoun
 				newMemHashes = append(newMemHashes, mHash)
 			}
 		}
-		newMemHashes = append(newMemHashes, hash) // it's important to make it last
+		newMemHashes = append(newMemHashes, ton.Bits256(message.Hash())) // it's important to make it last
 		h.mempoolEmulate.accountsTraces.Set(account, newMemHashes, cache.WithExpiration(time.Second*time.Duration(ttl)))
 	}
 	emulationCh <- blockchain.ExtInMsgCopy{
diff --git a/pkg/api/event_handlers.go b/pkg/api/event_handlers.go
index 6c7bb6fe..a9fadb32 100644
--- a/pkg/api/event_handlers.go
+++ b/pkg/api/event_handlers.go
@@ -392,16 +392,12 @@ func (h *Handler) EmulateMessageToEvent(ctx context.Context, request *oas.Emulat
 	if err != nil {
 		return nil, toError(http.StatusBadRequest, err)
 	}
-	hash, err := c.Hash256()
-	if err != nil {
+	var message tlb.Message
+	if err = tlb.Unmarshal(c, &message); err != nil {
 		return nil, toError(http.StatusBadRequest, err)
 	}
-	trace, prs := h.mempoolEmulate.traces.Get(hash)
+	trace, prs := h.mempoolEmulate.traces.Get(ton.Bits256(message.Hash()))
 	if !prs {
-		var m tlb.Message
-		if err := tlb.Unmarshal(c, &m); err != nil {
-			return nil, toError(http.StatusBadRequest, err)
-		}
 		configBase64, err := h.storage.TrimmedConfigBase64()
 		if err != nil {
 			return nil, toError(http.StatusInternalServerError, err)
@@ -418,7 +414,7 @@ func (h *Handler) EmulateMessageToEvent(ctx context.Context, request *oas.Emulat
 		if err != nil {
 			return nil, toError(http.StatusInternalServerError, err)
 		}
-		tree, err := emulator.Run(ctx, m)
+		tree, err := emulator.Run(ctx, message)
 		if err != nil {
 			return nil, toProperEmulationError(err)
 		}
@@ -444,17 +440,12 @@ func (h *Handler) EmulateMessageToTrace(ctx context.Context, request *oas.Emulat
 	if err != nil {
 		return nil, toError(http.StatusBadRequest, err)
 	}
-	hash, err := c.Hash256()
-	if err != nil {
+	var message tlb.Message
+	if err = tlb.Unmarshal(c, &message); err != nil {
 		return nil, toError(http.StatusBadRequest, err)
 	}
-	trace, prs := h.mempoolEmulate.traces.Get(hash)
+	trace, prs := h.mempoolEmulate.traces.Get(ton.Bits256(message.Hash()))
 	if !prs {
-		var m tlb.Message
-		err = tlb.Unmarshal(c, &m)
-		if err != nil {
-			return nil, toError(http.StatusBadRequest, err)
-		}
 		configBase64, err := h.storage.TrimmedConfigBase64()
 		if err != nil {
 			return nil, toError(http.StatusInternalServerError, err)
@@ -466,12 +457,11 @@ func (h *Handler) EmulateMessageToTrace(ctx context.Context, request *oas.Emulat
 		if !params.IgnoreSignatureCheck.Value {
 			options = append(options, txemulator.WithSignatureCheck())
 		}
-
 		emulator, err := txemulator.NewTraceBuilder(options...)
 		if err != nil {
 			return nil, toError(http.StatusInternalServerError, err)
 		}
-		tree, err := emulator.Run(ctx, m)
+		tree, err := emulator.Run(ctx, message)
 		if err != nil {
 			return nil, toProperEmulationError(err)
 		}