diff --git a/ompi/mca/coll/libnbc/coll_libnbc.h b/ompi/mca/coll/libnbc/coll_libnbc.h
index 553f184095..2946f12570 100644
--- a/ompi/mca/coll/libnbc/coll_libnbc.h
+++ b/ompi/mca/coll/libnbc/coll_libnbc.h
@@ -62,7 +62,7 @@ struct ompi_coll_libnbc_component_t {
     mca_coll_base_component_2_0_0_t super;
     ompi_free_list_t requests;
     opal_list_t active_requests;
-    uint32_t active_comms;
+    int32_t active_comms;
     opal_atomic_lock_t progress_lock;
 };
 typedef struct ompi_coll_libnbc_component_t ompi_coll_libnbc_component_t;
diff --git a/ompi/mca/coll/libnbc/coll_libnbc_component.c b/ompi/mca/coll/libnbc/coll_libnbc_component.c
index e9a9f08b72..11735fdc0a 100644
--- a/ompi/mca/coll/libnbc/coll_libnbc_component.c
+++ b/ompi/mca/coll/libnbc/coll_libnbc_component.c
@@ -270,7 +270,7 @@ libnbc_module_destruct(ompi_coll_libnbc_module_t *module)
 
     /* if we ever were used for a collective op, do the progress cleanup. */
     if (true == module->comm_registered) {
-        uint64_t tmp = 
+        int32_t tmp = 
             OPAL_THREAD_ADD32(&mca_coll_libnbc_component.active_comms, -1);
         if (0 == tmp) {
             opal_progress_unregister(ompi_coll_libnbc_progress);
diff --git a/ompi/mca/coll/libnbc/nbc.c b/ompi/mca/coll/libnbc/nbc.c
index 3310053ca8..36476a59e4 100644
--- a/ompi/mca/coll/libnbc/nbc.c
+++ b/ompi/mca/coll/libnbc/nbc.c
@@ -556,7 +556,7 @@ int NBC_Init_handle(struct ompi_communicator_t *comm, ompi_coll_libnbc_request_t
 
   /* register progress */
   if (need_register) {
-      uint32_t tmp = 
+      int32_t tmp = 
           OPAL_THREAD_ADD32(&mca_coll_libnbc_component.active_comms, 1);
       if (tmp == 1) {
           opal_progress_register(ompi_coll_libnbc_progress);
diff --git a/ompi/mca/coll/libnbc/nbc_ialltoall.c b/ompi/mca/coll/libnbc/nbc_ialltoall.c
index 77d876b58c..f95b71981b 100644
--- a/ompi/mca/coll/libnbc/nbc_ialltoall.c
+++ b/ompi/mca/coll/libnbc/nbc_ialltoall.c
@@ -227,7 +227,7 @@ static inline int a2a_sched_linear(int rank, int p, MPI_Aint sndext, MPI_Aint rc
 
   for(r=0;r<p;r++) {
     /* easy algorithm */
-    if ((r == rank)) { continue; }
+    if (r == rank) { continue; }
     rbuf = ((char *) recvbuf) + (r*recvcount*rcvext);
     res = NBC_Sched_recv(rbuf, false, recvcount, recvtype, r, schedule);
     if (NBC_OK != res) { printf("Error in NBC_Sched_recv() (%i)\n", res); return res; }