diff --git a/ompi/mca/pml/ob1/pml_ob1_irecv.c b/ompi/mca/pml/ob1/pml_ob1_irecv.c
index 3010729fc0..4dc164b875 100644
--- a/ompi/mca/pml/ob1/pml_ob1_irecv.c
+++ b/ompi/mca/pml/ob1/pml_ob1_irecv.c
@@ -22,7 +22,6 @@
 #include "ompi/request/request.h"
 #include "pml_ob1_recvreq.h"
 #include "ompi/peruse/peruse-internal.h"
-#include "ompi/memchecker.h"
 
 int mca_pml_ob1_irecv_init(void *addr,
                            size_t count,
@@ -41,13 +40,6 @@ int mca_pml_ob1_irecv_init(void *addr,
     MCA_PML_OB1_RECV_REQUEST_INIT(recvreq,
                                    addr,
                                    count, datatype, src, tag, comm, true);
-    /*
-     * Receive request is initialized, let's start memory checking.
-     */
-    MEMCHECKER (
-        memchecker_convertor_call(&opal_memchecker_base_mem_noaccess,
-                                  &recvreq->req_recv.req_base.req_convertor);
-    );
     
     PERUSE_TRACE_COMM_EVENT (PERUSE_COMM_REQ_ACTIVATE,
                              &((recvreq)->req_recv.req_base),
diff --git a/ompi/mca/pml/ob1/pml_ob1_isend.c b/ompi/mca/pml/ob1/pml_ob1_isend.c
index 93b5384585..48f63dd1c0 100644
--- a/ompi/mca/pml/ob1/pml_ob1_isend.c
+++ b/ompi/mca/pml/ob1/pml_ob1_isend.c
@@ -24,7 +24,6 @@
 #include "pml_ob1_sendreq.h"
 #include "pml_ob1_recvreq.h"
 #include "ompi/peruse/peruse-internal.h"
-#include "ompi/memchecker.h"
 
 int mca_pml_ob1_isend_init(void *buf,
                            size_t count,
@@ -48,14 +47,6 @@ int mca_pml_ob1_isend_init(void *buf,
                                   datatype,
                                   dst, tag,
                                   comm, sendmode, true);
-
-    /*
-     * Send request is initialized, let's start memory checking.
-     */
-    MEMCHECKER (
-        memchecker_convertor_call(&opal_memchecker_base_mem_noaccess,
-                                  &sendreq->req_send.req_base.req_convertor);
-    );
     
     PERUSE_TRACE_COMM_EVENT (PERUSE_COMM_REQ_ACTIVATE,
                              &(sendreq)->req_send.req_base,
diff --git a/ompi/mca/pml/ob1/pml_ob1_recvreq.c b/ompi/mca/pml/ob1/pml_ob1_recvreq.c
index c81f85fa14..51a5506393 100644
--- a/ompi/mca/pml/ob1/pml_ob1_recvreq.c
+++ b/ompi/mca/pml/ob1/pml_ob1_recvreq.c
@@ -72,8 +72,10 @@ static int mca_pml_ob1_recv_request_free(struct ompi_request_t** request)
      * Package successfully received, make user buffer accessable.
      */
     MEMCHECKER(
-        memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                  &recvreq->req_recv.req_base.req_convertor);
+        memchecker_call(&opal_memchecker_base_mem_defined,
+                        recvreq->req_recv.req_base.req_addr,
+                        recvreq->req_recv.req_base.req_count,
+                        recvreq->req_recv.req_base.req_datatype);
     );
     *request = MPI_REQUEST_NULL;
     return OMPI_SUCCESS;
@@ -89,8 +91,10 @@ static int mca_pml_ob1_recv_request_cancel(struct ompi_request_t* ompi_request,
          * Receive request completed, make user buffer accessable.
          */
         MEMCHECKER(
-            memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                      &request->req_recv.req_base.req_convertor);
+            memchecker_call(&opal_memchecker_base_mem_defined,
+                            request->req_recv.req_base.req_addr,
+                            request->req_recv.req_base.req_count,
+                            request->req_recv.req_base.req_datatype);
         );
         return OMPI_SUCCESS;
     }
@@ -126,8 +130,10 @@ static int mca_pml_ob1_recv_request_cancel(struct ompi_request_t* ompi_request,
      * Receive request cancelled, make user buffer accessable.
      */
     MEMCHECKER(
-        memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                  &request->req_recv.req_base.req_convertor);
+        memchecker_call(&opal_memchecker_base_mem_defined,
+                        request->req_recv.req_base.req_addr,
+                        request->req_recv.req_base.req_count,
+                        request->req_recv.req_base.req_datatype);
     );
     return OMPI_SUCCESS;
 }
@@ -478,8 +484,10 @@ void mca_pml_ob1_recv_request_progress( mca_pml_ob1_recv_request_t* recvreq,
              *  Make user buffer accessible (defined) before unpacking.
              */
             MEMCHECKER(
-                memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                          &recvreq->req_recv.req_base.req_convertor);
+                memchecker_call(&opal_memchecker_base_mem_defined,
+                                recvreq->req_recv.req_base.req_addr,
+                                recvreq->req_recv.req_base.req_count,
+                                recvreq->req_recv.req_base.req_datatype);
             );
             MCA_PML_OB1_RECV_REQUEST_UNPACK( recvreq,
                                              segments,
@@ -492,8 +500,10 @@ void mca_pml_ob1_recv_request_progress( mca_pml_ob1_recv_request_t* recvreq,
              *  Unpacking finished, make the user buffer unaccessable again.
              */
             MEMCHECKER(
-                memchecker_convertor_call(&opal_memchecker_base_mem_noaccess,
-                                          &recvreq->req_recv.req_base.req_convertor);
+                memchecker_call(&opal_memchecker_base_mem_noaccess,
+                                recvreq->req_recv.req_base.req_addr,
+                                recvreq->req_recv.req_base.req_count,
+                                recvreq->req_recv.req_base.req_datatype);
             );
             break;
 
@@ -512,8 +522,10 @@ void mca_pml_ob1_recv_request_progress( mca_pml_ob1_recv_request_t* recvreq,
              */
             if( 0 < bytes_received ) {
                 MEMCHECKER(
-                    memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                              &recvreq->req_recv.req_base.req_convertor);
+                    memchecker_call(&opal_memchecker_base_mem_defined,
+                                    recvreq->req_recv.req_base.req_addr,
+                                    recvreq->req_recv.req_base.req_count,
+                                    recvreq->req_recv.req_base.req_datatype);
                 );
                 MCA_PML_OB1_RECV_REQUEST_UNPACK( recvreq,
                                                  segments,
@@ -523,8 +535,10 @@ void mca_pml_ob1_recv_request_progress( mca_pml_ob1_recv_request_t* recvreq,
                                                  bytes_received,
                                                  bytes_delivered );
                 MEMCHECKER(
-                    memchecker_convertor_call(&opal_memchecker_base_mem_noaccess,
-                                              &recvreq->req_recv.req_base.req_convertor);
+                    memchecker_call(&opal_memchecker_base_mem_noaccess,
+                                    recvreq->req_recv.req_base.req_addr,
+                                    recvreq->req_recv.req_base.req_count,
+                                    recvreq->req_recv.req_base.req_datatype);
                 );
             }
             break;
@@ -543,8 +557,10 @@ void mca_pml_ob1_recv_request_progress( mca_pml_ob1_recv_request_t* recvreq,
              *  Make user buffer accessable(defined) before unpacking.
              */
             MEMCHECKER(
-                memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                          &recvreq->req_recv.req_base.req_convertor);
+                memchecker_call(&opal_memchecker_base_mem_defined,
+                                recvreq->req_recv.req_base.req_addr,
+                                recvreq->req_recv.req_base.req_count,
+                                recvreq->req_recv.req_base.req_datatype);
             );
             MCA_PML_OB1_RECV_REQUEST_UNPACK( recvreq,
                                              segments,
@@ -557,8 +573,10 @@ void mca_pml_ob1_recv_request_progress( mca_pml_ob1_recv_request_t* recvreq,
              *  Unpacking finished, make the user buffer unaccessable again.
              */
             MEMCHECKER(
-                memchecker_convertor_call(&opal_memchecker_base_mem_noaccess,
-                                          &recvreq->req_recv.req_base.req_convertor);
+                memchecker_call(&opal_memchecker_base_mem_noaccess,
+                                recvreq->req_recv.req_base.req_addr,
+                                recvreq->req_recv.req_base.req_count,
+                                recvreq->req_recv.req_base.req_datatype);
             );
             break;
 
diff --git a/ompi/mca/pml/ob1/pml_ob1_sendreq.c b/ompi/mca/pml/ob1/pml_ob1_sendreq.c
index 6d679df325..9573e4653c 100644
--- a/ompi/mca/pml/ob1/pml_ob1_sendreq.c
+++ b/ompi/mca/pml/ob1/pml_ob1_sendreq.c
@@ -104,8 +104,10 @@ static int mca_pml_ob1_send_request_free(struct ompi_request_t** request)
 
     OPAL_THREAD_UNLOCK(&ompi_request_lock);
     MEMCHECKER(
-        memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                  &sendreq->req_send.req_base.req_convertor);
+        memchecker_call(&opal_memchecker_base_mem_defined,
+                        sendreq->req_send.req_base.req_addr,
+                        sendreq->req_send.req_base.req_count,
+                        sendreq->req_send.req_base.req_datatype);
     );
     *request = MPI_REQUEST_NULL;
     return OMPI_SUCCESS;
@@ -439,8 +441,10 @@ int mca_pml_ob1_send_request_start_copy( mca_pml_ob1_send_request_t* sendreq,
          * accessable.
          */
         MEMCHECKER(
-            memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                      &sendreq->req_send.req_base.req_convertor);
+            memchecker_call(&opal_memchecker_base_mem_defined,
+                            sendreq->req_send.req_base.req_addr,
+                            sendreq->req_send.req_base.req_count,
+                            sendreq->req_send.req_base.req_datatype);
         );
         (void)ompi_convertor_pack( &sendreq->req_send.req_base.req_convertor,
                                    &iov, &iov_count, &max_data );
@@ -448,8 +452,10 @@ int mca_pml_ob1_send_request_start_copy( mca_pml_ob1_send_request_t* sendreq,
           *  Packing finished, make the user buffer unaccessable.
           */
         MEMCHECKER(
-            memchecker_convertor_call(&opal_memchecker_base_mem_noaccess,
-                                      &sendreq->req_send.req_base.req_convertor);
+            memchecker_call(&opal_memchecker_base_mem_noaccess,
+                            sendreq->req_send.req_base.req_addr,
+                            sendreq->req_send.req_base.req_count,
+                            sendreq->req_send.req_base.req_datatype);
         );
     }
 
@@ -580,8 +586,10 @@ int mca_pml_ob1_send_request_start_rdma(
         size_t old_position = sendreq->req_send.req_base.req_convertor.bConverted;
 
         MEMCHECKER(
-            memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                      &sendreq->req_send.req_base.req_convertor);
+            memchecker_call(&opal_memchecker_base_mem_defined,
+                            sendreq->req_send.req_base.req_addr,
+                            sendreq->req_send.req_base.req_count,
+                            sendreq->req_send.req_base.req_datatype);
         );
         /* prepare source descriptor/segment(s) */
         /* PML owns this descriptor and will free it in */
@@ -595,8 +603,10 @@ int mca_pml_ob1_send_request_start_rdma(
                                   0,
                                   &src );
         MEMCHECKER(
-            memchecker_convertor_call(&opal_memchecker_base_mem_noaccess,
-                                      &sendreq->req_send.req_base.req_convertor);
+            memchecker_call(&opal_memchecker_base_mem_noaccess,
+                            sendreq->req_send.req_base.req_addr,
+                            sendreq->req_send.req_base.req_count,
+                            sendreq->req_send.req_base.req_datatype);
         );
         if( OPAL_UNLIKELY(NULL == src) ) {
             ompi_convertor_set_position(&sendreq->req_send.req_base.req_convertor,
@@ -727,8 +737,10 @@ int mca_pml_ob1_send_request_start_rndv( mca_pml_ob1_send_request_t* sendreq,
                             MCA_BTL_DES_FLAGS_PRIORITY | MCA_BTL_DES_FLAGS_BTL_OWNERSHIP ); 
     } else {
         MEMCHECKER(
-            memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                      &sendreq->req_send.req_base.req_convertor);
+            memchecker_call(&opal_memchecker_base_mem_defined,
+                            sendreq->req_send.req_base.req_addr,
+                            sendreq->req_send.req_base.req_count,
+                            sendreq->req_send.req_base.req_datatype);
         );
         mca_bml_base_prepare_src( bml_btl, 
                                   NULL,
@@ -739,8 +751,10 @@ int mca_pml_ob1_send_request_start_rndv( mca_pml_ob1_send_request_t* sendreq,
                                   MCA_BTL_DES_FLAGS_PRIORITY | MCA_BTL_DES_FLAGS_BTL_OWNERSHIP,
                                   &des );
         MEMCHECKER(
-            memchecker_convertor_call(&opal_memchecker_base_mem_noaccess,
-                                      &sendreq->req_send.req_base.req_convertor);
+            memchecker_call(&opal_memchecker_base_mem_noaccess,
+                            sendreq->req_send.req_base.req_addr,
+                            sendreq->req_send.req_base.req_count,
+                            sendreq->req_send.req_base.req_datatype);
         );
     }
 
@@ -934,8 +948,10 @@ cannot_pack:
 
         data_remaining = size;
         MEMCHECKER(
-            memchecker_convertor_call(&opal_memchecker_base_mem_defined,
-                                      &sendreq->req_send.req_base.req_convertor);
+            memchecker_call(&opal_memchecker_base_mem_defined,
+                            sendreq->req_send.req_base.req_addr,
+                            sendreq->req_send.req_base.req_count,
+                            sendreq->req_send.req_base.req_datatype);
         );
         mca_bml_base_prepare_src(bml_btl, NULL,
                                  &sendreq->req_send.req_base.req_convertor,
@@ -943,8 +959,10 @@ cannot_pack:
                                  sizeof(mca_pml_ob1_frag_hdr_t),
                                  &size, MCA_BTL_DES_FLAGS_BTL_OWNERSHIP, &des);
         MEMCHECKER(
-            memchecker_convertor_call(&opal_memchecker_base_mem_noaccess,
-                                      &sendreq->req_send.req_base.req_convertor);
+            memchecker_call(&opal_memchecker_base_mem_noaccess,
+                            sendreq->req_send.req_base.req_addr,
+                            sendreq->req_send.req_base.req_count,
+                            sendreq->req_send.req_base.req_datatype);
         );
 
         if( OPAL_UNLIKELY(des == NULL || size == 0) ) {
diff --git a/ompi/mpi/c/irecv.c b/ompi/mpi/c/irecv.c
index fecbe0081c..9e1afd9bb5 100644
--- a/ompi/mpi/c/irecv.c
+++ b/ompi/mpi/c/irecv.c
@@ -70,6 +70,9 @@ int MPI_Irecv(void *buf, int count, MPI_Datatype type, int source,
 
     OPAL_CR_ENTER_LIBRARY();
 
+    MEMCHECKER (
+        memchecker_call(&opal_memchecker_base_mem_noaccess, buf, count, type);
+    );
     rc = MCA_PML_CALL(irecv(buf,count,type,source,tag,comm,request));
     OMPI_ERRHANDLER_RETURN(rc, comm, rc, FUNC_NAME);
 }
diff --git a/ompi/mpi/c/isend.c b/ompi/mpi/c/isend.c
index 6fce52ee14..44d0687986 100644
--- a/ompi/mpi/c/isend.c
+++ b/ompi/mpi/c/isend.c
@@ -75,6 +75,9 @@ int MPI_Isend(void *buf, int count, MPI_Datatype type, int dest,
 
     OPAL_CR_ENTER_LIBRARY();
 
+    MEMCHECKER (
+        memchecker_call(&opal_memchecker_base_mem_noaccess, buf, count, type);
+    );
     rc = MCA_PML_CALL(isend(buf,count,type,dest,tag,MCA_PML_BASE_SEND_STANDARD,comm,request));
     OMPI_ERRHANDLER_RETURN(rc, comm, rc, FUNC_NAME);
 }