diff --git a/ompi/mca/pml/csum/pml_csum_recvfrag.c b/ompi/mca/pml/csum/pml_csum_recvfrag.c
index b8acd926b2..47d75b89f5 100644
--- a/ompi/mca/pml/csum/pml_csum_recvfrag.c
+++ b/ompi/mca/pml/csum/pml_csum_recvfrag.c
@@ -129,7 +129,10 @@ void mca_pml_csum_recv_frag_callback_match(mca_btl_base_module_t* btl,
 
     csum_received = hdr->hdr_common.hdr_csum;
     hdr->hdr_common.hdr_csum = 0;
-    csum = opal_csum16(hdr, sizeof(mca_pml_csum_match_hdr_t));
+#if OMPI_ENABLE_HETEROGENEOUS_SUPPORT
+    hdr->hdr_common.hdr_flags &= ~MCA_PML_CSUM_HDR_FLAGS_NBO;
+#endif
+    csum = opal_csum16(hdr, OMPI_PML_CSUM_MATCH_HDR_LEN);
     hdr->hdr_common.hdr_csum = csum_received;
     
     OPAL_OUTPUT_VERBOSE((5, mca_pml_base_output,
@@ -303,6 +306,9 @@ void mca_pml_csum_recv_frag_callback_rndv(mca_btl_base_module_t* btl,
     
     csum_received = hdr->hdr_common.hdr_csum;
     hdr->hdr_common.hdr_csum = 0;
+#if OMPI_ENABLE_HETEROGENEOUS_SUPPORT
+    hdr->hdr_common.hdr_flags &= ~MCA_PML_CSUM_HDR_FLAGS_NBO;
+#endif
     csum = opal_csum16(hdr, sizeof(mca_pml_csum_rendezvous_hdr_t));
     hdr->hdr_common.hdr_csum = csum_received;
     if (csum_received != csum) {
@@ -351,6 +357,9 @@ void mca_pml_csum_recv_frag_callback_ack(mca_btl_base_module_t* btl,
 
     csum_received = hdr->hdr_common.hdr_csum;
     hdr->hdr_common.hdr_csum = 0;
+#if OMPI_ENABLE_HETEROGENEOUS_SUPPORT
+    hdr->hdr_common.hdr_flags &= ~MCA_PML_CSUM_HDR_FLAGS_NBO;
+#endif
     csum = opal_csum16(hdr, sizeof(mca_pml_csum_ack_hdr_t)); 
     hdr->hdr_common.hdr_csum = csum_received;
     OPAL_OUTPUT_VERBOSE((1, mca_pml_base_output,
@@ -398,6 +407,9 @@ void mca_pml_csum_recv_frag_callback_frag(mca_btl_base_module_t* btl,
 
     csum_received = hdr->hdr_common.hdr_csum;
     hdr->hdr_common.hdr_csum = 0;
+#if OMPI_ENABLE_HETEROGENEOUS_SUPPORT
+    hdr->hdr_common.hdr_flags &= ~MCA_PML_CSUM_HDR_FLAGS_NBO;
+#endif
     csum = opal_csum16(hdr, sizeof(mca_pml_csum_frag_hdr_t)); 
     hdr->hdr_common.hdr_csum = csum_received;
     if(csum_received != csum) {
@@ -430,6 +442,9 @@ void mca_pml_csum_recv_frag_callback_put(mca_btl_base_module_t* btl,
     
     csum_received = hdr->hdr_common.hdr_csum;
     hdr->hdr_common.hdr_csum = 0;
+#if OMPI_ENABLE_HETEROGENEOUS_SUPPORT
+    hdr->hdr_common.hdr_flags &= ~MCA_PML_CSUM_HDR_FLAGS_NBO;
+#endif
     csum = opal_csum16(hdr, sizeof(mca_pml_csum_rdma_hdr_t)); 
     hdr->hdr_common.hdr_csum = csum_received;
     OPAL_OUTPUT_VERBOSE((1, mca_pml_base_output,
@@ -464,6 +479,9 @@ void mca_pml_csum_recv_frag_callback_fin(mca_btl_base_module_t* btl,
 
     csum_received = hdr->hdr_common.hdr_csum;
     hdr->hdr_common.hdr_csum = 0;
+#if OMPI_ENABLE_HETEROGENEOUS_SUPPORT
+    hdr->hdr_common.hdr_flags &= ~MCA_PML_CSUM_HDR_FLAGS_NBO;
+#endif
     csum = opal_csum16(hdr, sizeof(mca_pml_csum_fin_hdr_t)); 
     hdr->hdr_common.hdr_csum = csum_received;
     OPAL_OUTPUT_VERBOSE((1, mca_pml_base_output,
diff --git a/ompi/mca/pml/csum/pml_csum_sendreq.c b/ompi/mca/pml/csum/pml_csum_sendreq.c
index 46e5bac888..f02991be15 100644
--- a/ompi/mca/pml/csum/pml_csum_sendreq.c
+++ b/ompi/mca/pml/csum/pml_csum_sendreq.c
@@ -506,7 +506,7 @@ int mca_pml_csum_send_request_start_copy( mca_pml_csum_send_request_t* sendreq,
         match.hdr_seq = (uint16_t)sendreq->req_send.req_base.req_sequence;
         match.hdr_csum = (size > 0 ?
                                sendreq->req_send.req_base.req_convertor.checksum : OPAL_CSUM_ZERO);
-        match.hdr_common.hdr_csum = opal_csum16(&match, sizeof(mca_pml_csum_match_hdr_t));
+        match.hdr_common.hdr_csum = opal_csum16(&match, OMPI_PML_CSUM_MATCH_HDR_LEN);
         
         OPAL_OUTPUT_VERBOSE((1, mca_pml_base_output,
                              "%s:%s:%d Sending \'match\' with data csum:0x%x, header csum:0x%x, size:%lu \n",
@@ -585,7 +585,7 @@ int mca_pml_csum_send_request_start_copy( mca_pml_csum_send_request_t* sendreq,
     hdr->hdr_match.hdr_seq = (uint16_t)sendreq->req_send.req_base.req_sequence;
     hdr->hdr_match.hdr_csum = (size > 0 ?
         sendreq->req_send.req_base.req_convertor.checksum : OPAL_CSUM_ZERO);
-    hdr->hdr_common.hdr_csum = opal_csum16(hdr, sizeof(mca_pml_csum_match_hdr_t));
+    hdr->hdr_common.hdr_csum = opal_csum16(hdr, OMPI_PML_CSUM_MATCH_HDR_LEN);
     
     OPAL_OUTPUT_VERBOSE((5, mca_pml_base_output,
                          "%s:%s:%d common_hdr: %02x:%02x:%04x   match_hdr:  %04x:%04x:%08x:%08x:%08x",
@@ -667,7 +667,7 @@ int mca_pml_csum_send_request_start_prepare( mca_pml_csum_send_request_t* sendre
     hdr->hdr_match.hdr_seq = (uint16_t)sendreq->req_send.req_base.req_sequence;
     hdr->hdr_match.hdr_csum = (size > 0 ?
         sendreq->req_send.req_base.req_convertor.checksum : OPAL_CSUM_ZERO);
-    hdr->hdr_common.hdr_csum = opal_csum16(hdr, sizeof(mca_pml_csum_match_hdr_t));
+    hdr->hdr_common.hdr_csum = opal_csum16(hdr, OMPI_PML_CSUM_MATCH_HDR_LEN);
 
     OPAL_OUTPUT_VERBOSE((1, mca_pml_base_output,
                          "%s:%s:%d Sending \'match\' with data csum:0x%x, header csum:0x%x, size:%lu \n",