diff --git a/ompi/mca/coll/ucc/coll_ucc_allgather.c b/ompi/mca/coll/ucc/coll_ucc_allgather.c
index b620d9529a2..4be8f953fb3 100644
--- a/ompi/mca/coll/ucc/coll_ucc_allgather.c
+++ b/ompi/mca/coll/ucc/coll_ucc_allgather.c
@@ -9,8 +9,8 @@
 
 #include "coll_ucc_common.h"
 
-static inline ucc_status_t mca_coll_ucc_allgather_init(const void *sbuf, int scount, struct ompi_datatype_t *sdtype,
-                                                       void* rbuf, int rcount, struct ompi_datatype_t *rdtype,
+static inline ucc_status_t mca_coll_ucc_allgather_init(const void *sbuf, size_t scount, struct ompi_datatype_t *sdtype,
+                                                       void* rbuf, size_t rcount, struct ompi_datatype_t *rdtype,
                                                        mca_coll_ucc_module_t *ucc_module,
                                                        ucc_coll_req_h *req,
                                                        mca_coll_ucc_req_t *coll_req)
diff --git a/ompi/mca/coll/ucc/coll_ucc_allgatherv.c b/ompi/mca/coll/ucc/coll_ucc_allgatherv.c
index 6cf33a5dd80..aecd45bfe86 100644
--- a/ompi/mca/coll/ucc/coll_ucc_allgatherv.c
+++ b/ompi/mca/coll/ucc/coll_ucc_allgatherv.c
@@ -9,7 +9,7 @@
 
 #include "coll_ucc_common.h"
 
-static inline ucc_status_t mca_coll_ucc_allgatherv_init(const void *sbuf, int scount,
+static inline ucc_status_t mca_coll_ucc_allgatherv_init(const void *sbuf, size_t scount,
                                                         struct ompi_datatype_t *sdtype,
                                                         void* rbuf, const int *rcounts, const int *rdisps,
                                                         struct ompi_datatype_t *rdtype,
diff --git a/ompi/mca/coll/ucc/coll_ucc_allreduce.c b/ompi/mca/coll/ucc/coll_ucc_allreduce.c
index a46a59db337..fea5549a72c 100644
--- a/ompi/mca/coll/ucc/coll_ucc_allreduce.c
+++ b/ompi/mca/coll/ucc/coll_ucc_allreduce.c
@@ -9,7 +9,7 @@
 
 #include "coll_ucc_common.h"
 
-static inline ucc_status_t mca_coll_ucc_allreduce_init(const void *sbuf, void *rbuf, int count,
+static inline ucc_status_t mca_coll_ucc_allreduce_init(const void *sbuf, void *rbuf, size_t count,
                                                        struct ompi_datatype_t *dtype,
                                                        struct ompi_op_t *op, mca_coll_ucc_module_t *ucc_module,
                                                        ucc_coll_req_h *req,
diff --git a/ompi/mca/coll/ucc/coll_ucc_alltoall.c b/ompi/mca/coll/ucc/coll_ucc_alltoall.c
index d6871f23b69..2cacfc25b2a 100644
--- a/ompi/mca/coll/ucc/coll_ucc_alltoall.c
+++ b/ompi/mca/coll/ucc/coll_ucc_alltoall.c
@@ -9,8 +9,8 @@
 
 #include "coll_ucc_common.h"
 
-static inline ucc_status_t mca_coll_ucc_alltoall_init(const void *sbuf, int scount, struct ompi_datatype_t *sdtype,
-                                                      void* rbuf, int rcount, struct ompi_datatype_t *rdtype,
+static inline ucc_status_t mca_coll_ucc_alltoall_init(const void *sbuf, size_t scount, struct ompi_datatype_t *sdtype,
+                                                      void* rbuf, size_t rcount, struct ompi_datatype_t *rdtype,
                                                       mca_coll_ucc_module_t *ucc_module,
                                                       ucc_coll_req_h *req,
                                                       mca_coll_ucc_req_t *coll_req)
diff --git a/ompi/mca/coll/ucc/coll_ucc_bcast.c b/ompi/mca/coll/ucc/coll_ucc_bcast.c
index 661f336e64d..7406e6228a6 100644
--- a/ompi/mca/coll/ucc/coll_ucc_bcast.c
+++ b/ompi/mca/coll/ucc/coll_ucc_bcast.c
@@ -8,7 +8,7 @@
 
 #include "coll_ucc_common.h"
 
-static inline ucc_status_t mca_coll_ucc_bcast_init(void *buf, int count, struct ompi_datatype_t *dtype,
+static inline ucc_status_t mca_coll_ucc_bcast_init(void *buf, size_t count, struct ompi_datatype_t *dtype,
                                                    int root, mca_coll_ucc_module_t *ucc_module,
                                                    ucc_coll_req_h *req,
                                                    mca_coll_ucc_req_t *coll_req)
diff --git a/ompi/mca/coll/ucc/coll_ucc_reduce.c b/ompi/mca/coll/ucc/coll_ucc_reduce.c
index 66ff6659f01..28c1d6c1ae5 100644
--- a/ompi/mca/coll/ucc/coll_ucc_reduce.c
+++ b/ompi/mca/coll/ucc/coll_ucc_reduce.c
@@ -8,7 +8,7 @@
 
 #include "coll_ucc_common.h"
 
-static inline ucc_status_t mca_coll_ucc_reduce_init(const void *sbuf, void *rbuf, int count,
+static inline ucc_status_t mca_coll_ucc_reduce_init(const void *sbuf, void *rbuf, size_t count,
                                                     struct ompi_datatype_t *dtype,
                                                     struct ompi_op_t *op, int root,
                                                     mca_coll_ucc_module_t *ucc_module,