diff --git a/ompi/mca/coll/han/coll_han.h b/ompi/mca/coll/han/coll_han.h
index 9ec12cc8e6c..08abfe8970a 100644
--- a/ompi/mca/coll/han/coll_han.h
+++ b/ompi/mca/coll/han/coll_han.h
@@ -102,6 +102,7 @@ struct mca_coll_han_allreduce_args_s {
     int seg_count;
     int root_up_rank;
     int root_low_rank;
+    int root_reduce_low_rank;
     int num_segments;
     int cur_seg;
     int w_rank;
diff --git a/ompi/mca/coll/han/coll_han_allreduce.c b/ompi/mca/coll/han/coll_han_allreduce.c
index 039913d7fdb..0971a39f1b7 100644
--- a/ompi/mca/coll/han/coll_han_allreduce.c
+++ b/ompi/mca/coll/han/coll_han_allreduce.c
@@ -6,6 +6,8 @@
  *
  * Copyright (c) 2020      Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2022      IBM Corporation. All rights reserved
+ * Copyright (c) 2023      Computer Architecture and VLSI Systems (CARV)
+ *                         Laboratory, ICS Forth. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -22,6 +24,7 @@
 
 #include "coll_han.h"
 #include "ompi/mca/coll/base/coll_base_functions.h"
+#include "ompi/mca/coll/base/coll_base_util.h"
 #include "ompi/mca/coll/base/coll_tags.h"
 #include "ompi/mca/pml/pml.h"
 #include "coll_han_trigger.h"
@@ -43,6 +46,7 @@ mca_coll_han_set_allreduce_args(mca_coll_han_allreduce_args_t * args,
                                 struct ompi_op_t *op,
                                 int root_up_rank,
                                 int root_low_rank,
+                                int root_reduce_low_rank,
                                 struct ompi_communicator_t *up_comm,
                                 struct ompi_communicator_t *low_comm,
                                 int num_segments,
@@ -59,6 +63,7 @@ mca_coll_han_set_allreduce_args(mca_coll_han_allreduce_args_t * args,
     args->op = op;
     args->root_up_rank = root_up_rank;
     args->root_low_rank = root_low_rank;
+    args->root_reduce_low_rank = root_reduce_low_rank;
     args->up_comm = up_comm;
     args->low_comm = low_comm;
     args->num_segments = num_segments;
@@ -139,6 +144,17 @@ mca_coll_han_allreduce_intra(const void *sbuf,
     int low_rank = ompi_comm_rank(low_comm);
     int root_up_rank = 0;
     int root_low_rank = 0;
+    int root_reduce_low_rank = 0;
+
+    mca_coll_base_avail_coll_t *low_1st_module = (mca_coll_base_avail_coll_t *)
+        opal_list_get_last(low_comm->c_coll->module_list);
+
+    // Invoke XHC's "special" Reduce
+    if(0 == strcmp(low_1st_module->ac_component_name, "xhc")
+            && low_comm->c_coll->coll_reduce_module == low_1st_module->ac_module) {
+        root_reduce_low_rank = -1;
+    }
+
     /* Create t0 task for the first segment */
     mca_coll_task_t *t0 = OBJ_NEW(mca_coll_task_t);
     /* Setup up t0 task arguments */
@@ -146,8 +162,8 @@ mca_coll_han_allreduce_intra(const void *sbuf,
     completed[0] = 0;
     mca_coll_han_allreduce_args_t *t = malloc(sizeof(mca_coll_han_allreduce_args_t));
     mca_coll_han_set_allreduce_args(t, t0, (char *) sbuf, (char *) rbuf, seg_count, dtype, op,
-                                    root_up_rank, root_low_rank, up_comm, low_comm, num_segments, 0,
-                                    w_rank, count - (num_segments - 1) * seg_count,
+                                    root_up_rank, root_low_rank, root_reduce_low_rank, up_comm,
+                                    low_comm, num_segments, 0, w_rank, count - (num_segments - 1) * seg_count,
                                     low_rank != root_low_rank, NULL, completed);
     /* Init t0 task */
     init_task(t0, mca_coll_han_allreduce_t0_task, (void *) (t));
@@ -215,18 +231,18 @@ int mca_coll_han_allreduce_t0_task(void *task_args)
     if (MPI_IN_PLACE == t->sbuf) {
         if (!t->noop) {
             t->low_comm->c_coll->coll_reduce(MPI_IN_PLACE, (char *) t->rbuf, t->seg_count, t->dtype,
-                                             t->op, t->root_low_rank, t->low_comm,
+                                             t->op, t->root_reduce_low_rank, t->low_comm,
                                              t->low_comm->c_coll->coll_reduce_module);
         }
         else {
             t->low_comm->c_coll->coll_reduce((char *) t->rbuf, NULL, t->seg_count, t->dtype,
-                                             t->op, t->root_low_rank, t->low_comm,
+                                             t->op, t->root_reduce_low_rank, t->low_comm,
                                              t->low_comm->c_coll->coll_reduce_module);
         }
     }
     else {
         t->low_comm->c_coll->coll_reduce((char *) t->sbuf, (char *) t->rbuf, t->seg_count, t->dtype,
-                                         t->op, t->root_low_rank, t->low_comm,
+                                         t->op, t->root_reduce_low_rank, t->low_comm,
                                          t->low_comm->c_coll->coll_reduce_module);
     }
     return OMPI_SUCCESS;
@@ -267,21 +283,20 @@ int mca_coll_han_allreduce_t1_task(void *task_args)
             if (!t->noop) {
                 t->low_comm->c_coll->coll_reduce(MPI_IN_PLACE,
                                                  (char *) t->rbuf + extent * t->seg_count, tmp_count,
-                                                 t->dtype, t->op, t->root_low_rank, t->low_comm,
+                                                 t->dtype, t->op, t->root_reduce_low_rank, t->low_comm,
                                                  t->low_comm->c_coll->coll_reduce_module);
             } else {
                 t->low_comm->c_coll->coll_reduce((char *) t->rbuf + extent * t->seg_count,
                                                  NULL, tmp_count,
-                                                 t->dtype, t->op, t->root_low_rank, t->low_comm,
+                                                 t->dtype, t->op, t->root_reduce_low_rank, t->low_comm,
                                                  t->low_comm->c_coll->coll_reduce_module);
-
             }
         } else {
             t->low_comm->c_coll->coll_reduce((char *) t->sbuf + extent * t->seg_count,
                                              (char *) t->rbuf + extent * t->seg_count, tmp_count,
-                                             t->dtype, t->op, t->root_low_rank, t->low_comm,
+                                             t->dtype, t->op, t->root_reduce_low_rank, t->low_comm,
                                              t->low_comm->c_coll->coll_reduce_module);
-	}
+        }
     }
     if (!t->noop) {
         ompi_request_wait(&ireduce_req, MPI_STATUS_IGNORE);
@@ -337,25 +352,25 @@ int mca_coll_han_allreduce_t2_task(void *task_args)
             tmp_count = t->last_seg_count;
         }
 
-	if (t->sbuf == MPI_IN_PLACE) {
-	    if (!t->noop) {
-                t->low_comm->c_coll->coll_reduce(MPI_IN_PLACE,
+        if (t->sbuf == MPI_IN_PLACE) {
+            if (!t->noop) {
+                    t->low_comm->c_coll->coll_reduce(MPI_IN_PLACE,
+                                                     (char *) t->rbuf + 2 * extent * t->seg_count, tmp_count,
+                                                     t->dtype, t->op, t->root_reduce_low_rank, t->low_comm,
+                                                     t->low_comm->c_coll->coll_reduce_module);
+            } else {
+                    t->low_comm->c_coll->coll_reduce((char *) t->rbuf + 2 * extent * t->seg_count,
+                                                     NULL, tmp_count,
+                                                     t->dtype, t->op, t->root_reduce_low_rank, t->low_comm,
+                                                     t->low_comm->c_coll->coll_reduce_module);
+
+            }
+        } else {
+                t->low_comm->c_coll->coll_reduce((char *) t->sbuf + 2 * extent * t->seg_count,
                                                  (char *) t->rbuf + 2 * extent * t->seg_count, tmp_count,
-                                                 t->dtype, t->op, t->root_low_rank, t->low_comm,
-                                                 t->low_comm->c_coll->coll_reduce_module);
-	    } else {
-                t->low_comm->c_coll->coll_reduce((char *) t->rbuf + 2 * extent * t->seg_count,
-                                                 NULL, tmp_count,
-                                                 t->dtype, t->op, t->root_low_rank, t->low_comm,
+                                                 t->dtype, t->op, t->root_reduce_low_rank, t->low_comm,
                                                  t->low_comm->c_coll->coll_reduce_module);
-
-	    }
-	} else {
-            t->low_comm->c_coll->coll_reduce((char *) t->sbuf + 2 * extent * t->seg_count,
-                                             (char *) t->rbuf + 2 * extent * t->seg_count, tmp_count,
-                                             t->dtype, t->op, t->root_low_rank, t->low_comm,
-                                             t->low_comm->c_coll->coll_reduce_module);
-	}
+        }
     }
     if (!t->noop && req_count > 0) {
         ompi_request_wait_all(req_count, reqs, MPI_STATUSES_IGNORE);
@@ -421,18 +436,18 @@ int mca_coll_han_allreduce_t3_task(void *task_args)
             if (!t->noop) {
                 t->low_comm->c_coll->coll_reduce(MPI_IN_PLACE,
                                                  (char *) t->rbuf + 3 * extent * t->seg_count, tmp_count,
-                                                 t->dtype, t->op, t->root_low_rank, t->low_comm,
+                                                 t->dtype, t->op, t->root_reduce_low_rank, t->low_comm,
                                                  t->low_comm->c_coll->coll_reduce_module);
-	    } else {
+        } else {
                 t->low_comm->c_coll->coll_reduce((char *) t->rbuf + 3 * extent * t->seg_count,
                                                  NULL, tmp_count,
-                                                 t->dtype, t->op, t->root_low_rank, t->low_comm,
+                                                 t->dtype, t->op, t->root_reduce_low_rank, t->low_comm,
                                                  t->low_comm->c_coll->coll_reduce_module);
             }
         } else {
             t->low_comm->c_coll->coll_reduce((char *) t->sbuf + 3 * extent * t->seg_count,
                                              (char *) t->rbuf + 3 * extent * t->seg_count, tmp_count,
-                                             t->dtype, t->op, t->root_low_rank, t->low_comm,
+                                             t->dtype, t->op, t->root_reduce_low_rank, t->low_comm,
                                              t->low_comm->c_coll->coll_reduce_module);
         }
     }
@@ -473,6 +488,7 @@ mca_coll_han_allreduce_intra_simple(const void *sbuf,
     ompi_communicator_t *low_comm;
     ompi_communicator_t *up_comm;
     int root_low_rank = 0;
+    int root_reduce_low_rank = 0;
     int low_rank;
     int ret;
     mca_coll_han_module_t *han_module = (mca_coll_han_module_t *)module;
@@ -504,22 +520,31 @@ mca_coll_han_allreduce_intra_simple(const void *sbuf,
     up_comm = han_module->sub_comm[INTER_NODE];
     low_rank = ompi_comm_rank(low_comm);
 
+    mca_coll_base_avail_coll_t *low_1st_module = (mca_coll_base_avail_coll_t *)
+        opal_list_get_last(low_comm->c_coll->module_list);
+
+    // Invoke XHC's "special" Reduce
+    if(0 == strcmp(low_1st_module->ac_component_name, "xhc")
+            && low_comm->c_coll->coll_reduce_module == low_1st_module->ac_module) {
+        root_reduce_low_rank = -1;
+    }
+
     /* Low_comm reduce */
     if (MPI_IN_PLACE == sbuf) {
         if (low_rank == root_low_rank) {
             ret = low_comm->c_coll->coll_reduce(MPI_IN_PLACE, (char *)rbuf,
-                count, dtype, op, root_low_rank,
+                count, dtype, op, root_reduce_low_rank,
                 low_comm, low_comm->c_coll->coll_reduce_module);
         }
         else {
             ret = low_comm->c_coll->coll_reduce((char *)rbuf, NULL,
-                count, dtype, op, root_low_rank,
+                count, dtype, op, root_reduce_low_rank,
                 low_comm, low_comm->c_coll->coll_reduce_module);
         }
     }
     else {
         ret = low_comm->c_coll->coll_reduce((char *)sbuf, (char *)rbuf,
-                count, dtype, op, root_low_rank,
+                count, dtype, op, root_reduce_low_rank,
                 low_comm, low_comm->c_coll->coll_reduce_module);
     }
     if (OPAL_UNLIKELY(OMPI_SUCCESS != ret)) {