diff --git a/exchange/bitswap/bitswap.go b/exchange/bitswap/bitswap.go
index 37826c492..937ee131e 100644
--- a/exchange/bitswap/bitswap.go
+++ b/exchange/bitswap/bitswap.go
@@ -219,6 +219,15 @@ func (bs *Bitswap) HasBlock(ctx context.Context, blk *blocks.Block) error {
 		return errors.New("bitswap is closed")
 	default:
 	}
+	has, err := bs.blockstore.Has(blk.Key())
+	if err != nil {
+		return err
+	}
+
+	if has {
+		log.Error(bs.self, "Dup Block! ", blk.Key())
+	}
+
 	if err := bs.blockstore.Put(blk); err != nil {
 		return err
 	}
diff --git a/exchange/bitswap/bitswap_test.go b/exchange/bitswap/bitswap_test.go
index 85b3c0ec8..85a8e9d5d 100644
--- a/exchange/bitswap/bitswap_test.go
+++ b/exchange/bitswap/bitswap_test.go
@@ -69,9 +69,6 @@ func TestGetBlockFromPeerAfterPeerAnnounces(t *testing.T) {
 	hasBlock := g.Next()
 	defer hasBlock.Exchange.Close()
 
-	if err := hasBlock.Blockstore().Put(block); err != nil {
-		t.Fatal(err)
-	}
 	if err := hasBlock.Exchange.HasBlock(context.Background(), block); err != nil {
 		t.Fatal(err)
 	}
@@ -136,7 +133,6 @@ func PerformDistributionTest(t *testing.T, numInstances, numBlocks int) {
 	var blkeys []u.Key
 	first := instances[0]
 	for _, b := range blocks {
-		first.Blockstore().Put(b) // TODO remove. don't need to do this. bitswap owns block
 		blkeys = append(blkeys, b.Key())
 		first.Exchange.HasBlock(context.Background(), b)
 	}
@@ -144,7 +140,7 @@ func PerformDistributionTest(t *testing.T, numInstances, numBlocks int) {
 	t.Log("Distribute!")
 
 	wg := sync.WaitGroup{}
-	for _, inst := range instances {
+	for _, inst := range instances[1:] {
 		wg.Add(1)
 		go func(inst Instance) {
 			defer wg.Done()