diff --git a/itests/deals_concurrent_test.go b/itests/deals_concurrent_test.go
index 33a8218dd5c..44b25c7b36e 100644
--- a/itests/deals_concurrent_test.go
+++ b/itests/deals_concurrent_test.go
@@ -1,12 +1,22 @@
 package itests
 
 import (
+	"context"
 	"fmt"
+	"sync"
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
+	datatransfer "github.com/filecoin-project/go-data-transfer"
 	"github.com/filecoin-project/go-state-types/abi"
+
 	"github.com/filecoin-project/lotus/itests/kit"
+	"github.com/filecoin-project/lotus/node"
+	"github.com/filecoin-project/lotus/node/modules"
+	"github.com/filecoin-project/lotus/node/modules/dtypes"
+	"github.com/filecoin-project/lotus/node/repo"
 )
 
 func TestDealCyclesConcurrent(t *testing.T) {
@@ -47,3 +57,71 @@ func TestDealCyclesConcurrent(t *testing.T) {
 		t.Run(ns+"-stdretrieval-NoCAR", func(t *testing.T) { runTest(t, n, false, false) })
 	}
 }
+
+func TestSimultenousTransferLimit(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode")
+	}
+
+	kit.QuietMiningLogs()
+
+	blockTime := 10 * time.Millisecond
+
+	// For these tests where the block time is artificially short, just use
+	// a deal start epoch that is guaranteed to be far enough in the future
+	// so that the deal starts sealing in time
+	startEpoch := abi.ChainEpoch(2 << 12)
+
+	runTest := func(t *testing.T) {
+		client, miner, ens := kit.EnsembleMinimal(t, kit.MockProofs(), kit.ConstructorOpts(
+			node.ApplyIf(node.IsType(repo.StorageMiner), node.Override(new(dtypes.StagingGraphsync), modules.StagingGraphsync(2))),
+		))
+		ens.InterconnectAll().BeginMining(blockTime)
+		dh := kit.NewDealHarness(t, client, miner)
+
+		ctx, cancel := context.WithCancel(context.Background())
+
+		du, err := miner.MarketDataTransferUpdates(ctx)
+		require.NoError(t, err)
+
+		var maxOngoing int
+		var wg sync.WaitGroup
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+
+			ongoing := map[datatransfer.TransferID]struct{}{}
+
+			for {
+				select {
+				case u := <-du:
+					t.Logf("%d - %s", u.TransferID, datatransfer.Statuses[u.Status])
+					if u.Status == datatransfer.Ongoing {
+						ongoing[u.TransferID] = struct{}{}
+					} else {
+						delete(ongoing, u.TransferID)
+					}
+
+					if len(ongoing) > maxOngoing {
+						maxOngoing = len(ongoing)
+					}
+				case <-ctx.Done():
+					return
+				}
+			}
+		}()
+
+		dh.RunConcurrentDeals(kit.RunConcurrentDealsOpts{
+			N:             1, // TODO: set to 20 after https://github.com/ipfs/go-graphsync/issues/175 is fixed
+			FastRetrieval: true,
+			StartEpoch:    startEpoch,
+		})
+
+		cancel()
+		wg.Wait()
+
+		require.LessOrEqual(t, maxOngoing, 2)
+	}
+
+	runTest(t)
+}
diff --git a/node/builder.go b/node/builder.go
index f5294b8a359..884261a89b9 100644
--- a/node/builder.go
+++ b/node/builder.go
@@ -238,7 +238,7 @@ var LibP2P = Options(
 	Override(ConnGaterKey, lp2p.ConnGaterOption),
 )
 
-func isType(t repo.RepoType) func(s *Settings) bool {
+func IsType(t repo.RepoType) func(s *Settings) bool {
 	return func(s *Settings) bool { return s.nodeType == t }
 }
 
@@ -468,7 +468,7 @@ func Online() Option {
 		LibP2P,
 
 		ApplyIf(isFullOrLiteNode, ChainNode),
-		ApplyIf(isType(repo.StorageMiner), MinerNode),
+		ApplyIf(IsType(repo.StorageMiner), MinerNode),
 	)
 }
 
@@ -680,8 +680,8 @@ func Repo(r repo.Repo) Option {
 
 			Override(new(*dtypes.APIAlg), modules.APISecret),
 
-			ApplyIf(isType(repo.FullNode), ConfigFullNode(c)),
-			ApplyIf(isType(repo.StorageMiner), ConfigStorageMiner(c)),
+			ApplyIf(IsType(repo.FullNode), ConfigFullNode(c)),
+			ApplyIf(IsType(repo.StorageMiner), ConfigStorageMiner(c)),
 		)(settings)
 	}
 }