diff --git a/ompi/mca/btl/portals/btl_portals_component.c b/ompi/mca/btl/portals/btl_portals_component.c
index 002d2026cd..e98c99b57a 100644
--- a/ompi/mca/btl/portals/btl_portals_component.c
+++ b/ompi/mca/btl/portals/btl_portals_component.c
@@ -205,7 +205,7 @@ mca_btl_portals_component_open(void)
                            &dummy);
     mca_btl_portals_module.super.btl_bandwidth = dummy;
 
-#if 0
+#if 1
     mca_btl_portals_module.super.btl_flags = MCA_BTL_FLAGS_RDMA | MCA_BTL_FLAGS_SEND_INPLACE;
 #else
     mca_btl_portals_module.super.btl_flags = MCA_BTL_FLAGS_RDMA;
@@ -472,7 +472,8 @@ mca_btl_portals_component_progress(void)
                     OPAL_OUTPUT_VERBOSE((90, mca_btl_portals_component.portals_output,
                                          "received send fragment %x", frag));
                 
-                    if (ev.md.length - (ev.offset + ev.mlength) < ev.md.max_size) {
+                    if (ev.md.length - (ev.offset + ev.mlength) < ev.md.max_size ||
+                        ev.md.threshold == 0) {
                         /* the block is full.  It's deactivated automagically, but we
                            can't start it up again until everyone is done with it.
                            The actual reactivation and all that will happen after the
diff --git a/ompi/mca/btl/portals/btl_portals_recv.h b/ompi/mca/btl/portals/btl_portals_recv.h
index 75f1727bc5..0b7e8161da 100644
--- a/ompi/mca/btl/portals/btl_portals_recv.h
+++ b/ompi/mca/btl/portals/btl_portals_recv.h
@@ -94,7 +94,10 @@ mca_btl_portals_activate_block(mca_btl_portals_recv_block_t *block)
     /* and the memory descriptor */
     md.start = block->start;
     md.length = block->length;
-    md.threshold = PTL_MD_THRESH_INF;
+    /* try to throttle incoming sends so that we don't overrun the incoming
+       queue size */
+    md.threshold = mca_btl_portals_module.portals_eq_sizes[OMPI_BTL_PORTALS_EQ] /
+        mca_btl_portals_module.portals_recv_mds_num;
     md.max_size = block->btl->super.btl_max_send_size;
     md.options = PTL_MD_OP_PUT | PTL_MD_MAX_SIZE;
     md.user_ptr = block;