diff --git a/adder/single/dag_service.go b/adder/single/dag_service.go
index 865bfc26..13b5b9cb 100644
--- a/adder/single/dag_service.go
+++ b/adder/single/dag_service.go
@@ -31,8 +31,9 @@ type DAGService struct {
 	addParams api.AddParams
 	local     bool
 
-	bs     *adder.BlockStreamer
-	blocks chan api.NodeWithMeta
+	bs           *adder.BlockStreamer
+	blocks       chan api.NodeWithMeta
+	recentBlocks *recentBlocks
 }
 
 // New returns a new Adder with the given rpc Client. The client is used
@@ -41,17 +42,24 @@ func New(ctx context.Context, rpc *rpc.Client, opts api.AddParams, local bool) *
 	// ensure don't Add something and pin it in direct mode.
 	opts.Mode = api.PinModeRecursive
 	return &DAGService{
-		ctx:       ctx,
-		rpcClient: rpc,
-		dests:     nil,
-		addParams: opts,
-		local:     local,
-		blocks:    make(chan api.NodeWithMeta, 256),
+		ctx:          ctx,
+		rpcClient:    rpc,
+		dests:        nil,
+		addParams:    opts,
+		local:        local,
+		blocks:       make(chan api.NodeWithMeta, 256),
+		recentBlocks: &recentBlocks{},
 	}
 }
 
 // Add puts the given node in the destination peers.
 func (dgs *DAGService) Add(ctx context.Context, node ipld.Node) error {
+	// Avoid adding the same node multiple times in a row.
+	// This is done by the ipfsadd-er, because some nodes are added
+	// via dagbuilder, then via MFS, and root nodes once more.
+	if dgs.recentBlocks.Has(node) {
+		return nil
+	}
 
 	// FIXME: can't this happen on initialization?  Perhaps the point here
 	// is the adder only allocates and starts streaming when the first
@@ -96,6 +104,7 @@ func (dgs *DAGService) Add(ctx context.Context, node ipld.Node) error {
 	case <-dgs.ctx.Done():
 		return ctx.Err()
 	case dgs.blocks <- adder.IpldNodeToNodeWithMeta(node):
+		dgs.recentBlocks.Add(node)
 		return nil
 	}
 }
@@ -152,3 +161,18 @@ func (dgs *DAGService) AddMany(ctx context.Context, nodes []ipld.Node) error {
 	}
 	return nil
 }
+
+type recentBlocks struct {
+	blocks [2]cid.Cid
+	cur    int
+}
+
+func (rc *recentBlocks) Add(n ipld.Node) {
+	rc.blocks[rc.cur] = n.Cid()
+	rc.cur = (rc.cur + 1) % 2
+}
+
+func (rc *recentBlocks) Has(n ipld.Node) bool {
+	c := n.Cid()
+	return rc.blocks[0].Equals(c) || rc.blocks[1].Equals(c)
+}
diff --git a/ipfsconn/ipfshttp/ipfshttp.go b/ipfsconn/ipfshttp/ipfshttp.go
index 1d0513ff..c1129834 100644
--- a/ipfsconn/ipfshttp/ipfshttp.go
+++ b/ipfsconn/ipfshttp/ipfshttp.go
@@ -596,7 +596,7 @@ func (ipfs *Connector) PinLsCid(ctx context.Context, pin api.Pin) (api.IPFSPinSt
 }
 
 func (ipfs *Connector) doPostCtx(ctx context.Context, client *http.Client, apiURL, path string, contentType string, postBody io.Reader) (*http.Response, error) {
-	logger.Debugf("posting %s", path)
+	logger.Debugf("posting /%s", path)
 	urlstr := fmt.Sprintf("%s/%s", apiURL, path)
 
 	req, err := http.NewRequest("POST", urlstr, postBody)
@@ -950,9 +950,7 @@ func (ci *chanIterator) Node() files.Node {
 		return nil
 	}
 	ci.seenMu.Lock()
-	if ci.seen.Visit(ci.current.Cid) {
-		logger.Debugf("block %s", ci.current.Cid)
-	}
+	ci.seen.Add(ci.current.Cid)
 	ci.seenMu.Unlock()
 	return files.NewBytesFile(ci.current.Data)
 }
@@ -1007,6 +1005,7 @@ func (ci *chanIterator) Next() bool {
 			ci.done = true
 			return false
 		}
+		logger.Debugf("block %s", next.Cid)
 		ci.current = next
 		return true
 	}