diff --git a/ompi/mca/btl/tcp/btl_tcp_proc.c b/ompi/mca/btl/tcp/btl_tcp_proc.c
index 17202d49c5..4b20bea544 100644
--- a/ompi/mca/btl/tcp/btl_tcp_proc.c
+++ b/ompi/mca/btl/tcp/btl_tcp_proc.c
@@ -132,7 +132,7 @@ mca_btl_tcp_proc_t* mca_btl_tcp_proc_create(ompi_proc_t* ompi_proc)
     }
     if(0 != (size % sizeof(mca_btl_tcp_addr_t))) {
         BTL_ERROR(("mca_base_modex_recv: invalid size %lu: btl-size: %lu\n",
-          (unsigned long) size, sizeof(mca_btl_tcp_addr_t)));
+          (unsigned long) size, (unsigned long)sizeof(mca_btl_tcp_addr_t)));
         return NULL;
     }
     btl_proc->proc_addr_count = size / sizeof(mca_btl_tcp_addr_t);
diff --git a/ompi/mca/pml/csum/pml_csum_recvfrag.c b/ompi/mca/pml/csum/pml_csum_recvfrag.c
index 534e9f09e2..8f3513160d 100644
--- a/ompi/mca/pml/csum/pml_csum_recvfrag.c
+++ b/ompi/mca/pml/csum/pml_csum_recvfrag.c
@@ -76,7 +76,7 @@ static void dump_csum_error_data(mca_btl_base_segment_t* segments, size_t num_se
     
     printf("CHECKSUM ERROR DATA\n");
     for (i = 0; i < num_segments; ++i) {
-        printf("Segment %lu", i);
+        printf("Segment %lu", (unsigned long)i);
         data = (uint8_t*)segments[i].seg_addr.pval;
         for (j=0; j < segments[i].seg_len; j++) {
             if (0 == (j % 40)) {
diff --git a/ompi/mca/pml/csum/pml_csum_recvreq.c b/ompi/mca/pml/csum/pml_csum_recvreq.c
index cf7717f7d5..cd41fff234 100644
--- a/ompi/mca/pml/csum/pml_csum_recvreq.c
+++ b/ompi/mca/pml/csum/pml_csum_recvreq.c
@@ -55,7 +55,7 @@ static void dump_csum_error_data(mca_btl_base_segment_t* segments, size_t num_se
     
     printf("CHECKSUM ERROR DATA\n");
     for (i = 0; i < num_segments; ++i) {
-        printf("Segment %lu", i);
+        printf("Segment %lu", (unsigned long)i);
         data = (uint8_t*)segments[i].seg_addr.pval;
         for (j=0; j < segments[i].seg_len; j++) {
             if (0 == (j % 40)) {