diff --git a/cpp/src/dbscan/mergelabels/tree_reduction.cuh b/cpp/src/dbscan/mergelabels/tree_reduction.cuh
index dd2630b01f..061657aace 100644
--- a/cpp/src/dbscan/mergelabels/tree_reduction.cuh
+++ b/cpp/src/dbscan/mergelabels/tree_reduction.cuh
@@ -39,12 +39,13 @@ void tree_reduction(const raft::handle_t& handle,
   const auto& comm = handle.get_comms();
   int my_rank      = comm.get_rank();
   int n_rank       = comm.get_size();
-  raft::comms::request_t request;
 
   int s = 1;
   while (s < n_rank) {
     CUML_LOG_DEBUG("Tree reduction, s=", s);
 
+    raft::comms::request_t request;
+
     // Find out whether the node is a receiver / sender / passive
     bool receiver = my_rank % (2 * s) == 0 && my_rank + s < n_rank;
     bool sender   = my_rank % (2 * s) == s;
@@ -57,7 +58,7 @@ void tree_reduction(const raft::handle_t& handle,
       comm.isend(labels, N, my_rank - s, 0, &request);
     }
 
-    comm.waitall(1, &request);
+    if (receiver || sender) { comm.waitall(1, &request); }
 
     if (receiver) {
       CUML_LOG_DEBUG("--> Merge labels");
diff --git a/python/cuml/cuml/dask/cluster/dbscan.py b/python/cuml/cuml/dask/cluster/dbscan.py
index 2fd9192ee2..09cbe42b67 100644
--- a/python/cuml/cuml/dask/cluster/dbscan.py
+++ b/python/cuml/cuml/dask/cluster/dbscan.py
@@ -104,8 +104,12 @@ def fit(self, X, out_dtype="int32"):
 
         data = self.client.scatter(X, broadcast=True)
 
-        comms = Comms(comms_p2p=True)
-        comms.init()
+        # Get the workers that actually hold the scattered data
+        who_has = self.client.who_has(data)
+        workers = list(who_has[data.key])
+
+        comms = Comms(comms_p2p=True, client=self.client)
+        comms.init(workers=workers)
 
         # Get worker info to map workers to their RAFT ranks
         worker_info = comms.worker_info(comms.worker_addresses)