diff --git a/ompi/mca/pml/base/pml_base_bsend.c b/ompi/mca/pml/base/pml_base_bsend.c
index a917412ff33..d1c38e90209 100644
--- a/ompi/mca/pml/base/pml_base_bsend.c
+++ b/ompi/mca/pml/base/pml_base_bsend.c
@@ -133,7 +133,7 @@ static int mca_pml_base_bsend_fini (void)
 /*
  * User-level call to attach buffer.
  */
-int mca_pml_base_bsend_attach(void* addr, int size)
+int mca_pml_base_bsend_attach(void* addr, size_t size)
 {
     int align;
 
@@ -179,7 +179,7 @@ int mca_pml_base_bsend_attach(void* addr, int size)
 /*
  * User-level call to detach buffer
  */
-int mca_pml_base_bsend_detach(void* addr, int* size)
+int mca_pml_base_bsend_detach(void* addr, size_t* size)
 {
     OPAL_THREAD_LOCK(&mca_pml_bsend_mutex);
 
@@ -201,7 +201,7 @@ int mca_pml_base_bsend_detach(void* addr, int* size)
     if(NULL != addr)
         *((void**)addr) = mca_pml_bsend_userbase;
     if(NULL != size)
-        *size = (int)mca_pml_bsend_usersize;
+        *size = mca_pml_bsend_usersize;
 
     /* reset local variables */
     mca_pml_bsend_userbase = NULL;
diff --git a/ompi/mca/pml/base/pml_base_bsend.h b/ompi/mca/pml/base/pml_base_bsend.h
index 725427e27f1..0d3c47a7ca5 100644
--- a/ompi/mca/pml/base/pml_base_bsend.h
+++ b/ompi/mca/pml/base/pml_base_bsend.h
@@ -30,8 +30,8 @@ BEGIN_C_DECLS
 
 OMPI_DECLSPEC int mca_pml_base_bsend_init (void);
 
-int mca_pml_base_bsend_attach(void* addr, int size);
-int mca_pml_base_bsend_detach(void* addr, int* size);
+int mca_pml_base_bsend_attach(void* addr, size_t size);
+int mca_pml_base_bsend_detach(void* addr, size_t* size);
 
 OMPI_DECLSPEC int mca_pml_base_bsend_request_alloc(ompi_request_t*);
 OMPI_DECLSPEC int mca_pml_base_bsend_request_start(ompi_request_t*);
diff --git a/ompi/mpi/c/buffer_attach.c b/ompi/mpi/c/buffer_attach.c
index be9a43adad6..ab28ffba31e 100644
--- a/ompi/mpi/c/buffer_attach.c
+++ b/ompi/mpi/c/buffer_attach.c
@@ -41,15 +41,15 @@ int MPI_Buffer_attach(void *buffer, int size)
 {
     int ret = OMPI_SUCCESS;
 
-  if (MPI_PARAM_CHECK) {
-    OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
-    if (NULL == buffer || size < 0) {
-      return OMPI_ERRHANDLER_NOHANDLE_INVOKE(MPI_ERR_ARG, FUNC_NAME);
+    if (MPI_PARAM_CHECK) {
+        OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
+        if (NULL == buffer || size < 0) {
+           return OMPI_ERRHANDLER_NOHANDLE_INVOKE(MPI_ERR_ARG, FUNC_NAME);
+        }
     }
-  }
 
-  ret = mca_pml_base_bsend_attach(buffer, size);
+    ret = mca_pml_base_bsend_attach(buffer, size);
 
-  return ret;
+    return ret;
 }
 
diff --git a/ompi/mpi/c/buffer_detach.c b/ompi/mpi/c/buffer_detach.c
index 9c5cd9e60a2..f50bb609f63 100644
--- a/ompi/mpi/c/buffer_detach.c
+++ b/ompi/mpi/c/buffer_detach.c
@@ -39,16 +39,20 @@ static const char FUNC_NAME[] = "MPI_Buffer_detach";
 
 int MPI_Buffer_detach(void *buffer, int *size)
 {
+    size_t size_arg;
     int ret = OMPI_SUCCESS;
 
-  if (MPI_PARAM_CHECK) {
-    OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
-    if (NULL == buffer || NULL == size) {
-      return OMPI_ERRHANDLER_NOHANDLE_INVOKE(MPI_ERR_ARG, FUNC_NAME);
+    if (MPI_PARAM_CHECK) {
+        OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
+        if (NULL == buffer || NULL == size) {
+            return OMPI_ERRHANDLER_NOHANDLE_INVOKE(MPI_ERR_ARG, FUNC_NAME);
+        }
     }
-  }
 
-  ret = mca_pml_base_bsend_detach(buffer, size);
+    ret = mca_pml_base_bsend_detach(buffer, &size_arg);
+    if (MPI_SUCCESS == ret) {
+        *size = (int)size_arg;
+    }
 
-  return ret;
+    return ret;
 }