diff --git a/src/mpi.f90 b/src/mpi.f90
index 7f7be74..cee58d9 100644
--- a/src/mpi.f90
+++ b/src/mpi.f90
@@ -178,17 +178,21 @@ subroutine MPI_Finalize_proc(ierr)
         end if
     end subroutine
 
-    subroutine MPI_Comm_size_proc(comm, size, ierr)
-        use mpi_c_bindings, only: c_mpi_comm_size
+    subroutine MPI_Comm_size_proc(comm, size, ierror)
+        use mpi_c_bindings, only: c_mpi_comm_size, c_mpi_comm_f2c
+        use iso_c_binding, only: c_int, c_ptr
         integer, intent(in) :: comm
         integer, intent(out) :: size
-        integer, optional, intent(out) :: ierr
+        integer, optional, intent(out) :: ierror
         integer :: local_ierr
-        if (present(ierr)) then
-            call c_mpi_comm_size(comm, size, ierr)
+        type(c_ptr) :: c_comm
+
+        c_comm = c_mpi_comm_f2c(comm)
+        local_ierr = c_mpi_comm_size(c_comm, size)
+        if (present(ierror)) then
+            ierror = local_ierr
         else
-            call c_mpi_comm_size(comm, size, local_ierr)
-            if (local_ierr /= 0) then
+            if (local_ierr /= MPI_SUCCESS) then
                 print *, "MPI_Comm_size failed with error code: ", local_ierr
             end if
         end if
diff --git a/src/mpi_c_bindings.f90 b/src/mpi_c_bindings.f90
index b827e2a..19eb336 100644
--- a/src/mpi_c_bindings.f90
+++ b/src/mpi_c_bindings.f90
@@ -2,6 +2,12 @@ module mpi_c_bindings
     implicit none
 
     interface
+        function c_mpi_comm_f2c(comm_f) bind(C, name="get_c_comm_from_fortran")
+            use iso_c_binding, only: c_int, c_ptr
+            integer(c_int), value :: comm_f
+            type(c_ptr) :: c_mpi_comm_f2c  ! MPI_Comm as pointer
+        end function c_mpi_comm_f2c
+
         function c_mpi_init(argc, argv) bind(C, name="MPI_Init")
             use iso_c_binding, only : c_int, c_ptr
             !> TODO: is the intent need to be explicitly specified
@@ -25,12 +31,12 @@ integer(c_int) function c_mpi_finalize() bind(C, name="MPI_Finalize")
             use iso_c_binding, only : c_int
         end function c_mpi_finalize
 
-        subroutine c_mpi_comm_size(comm, size, ierr) bind(C, name="mpi_comm_size_wrapper")
-            use iso_c_binding, only: c_int
-            integer(c_int), intent(in) :: comm
+        function c_mpi_comm_size(comm, size) bind(C, name="MPI_Comm_size")
+            use iso_c_binding, only: c_int, c_ptr
+            type(c_ptr), value :: comm
             integer(c_int), intent(out) :: size
-            integer(c_int), intent(out) :: ierr
-        end subroutine c_mpi_comm_size
+            integer(c_int) :: c_mpi_comm_size
+        end function c_mpi_comm_size
 
         subroutine c_mpi_bcast_int(buffer, count, datatype, root, comm, ierror) bind(C, name="mpi_bcast_int_wrapper")
             use iso_c_binding, only: c_int
@@ -132,11 +138,6 @@ function c_mpi_wtime() result(time) bind(C, name="MPI_Wtime")
             use iso_c_binding, only: c_double
             real(c_double) :: time
         end function
-        function c_mpi_comm_f2c(comm_f) bind(C, name="get_c_comm_from_fortran")
-            use iso_c_binding, only: c_int, c_ptr
-            integer(c_int), value :: comm_f
-            type(c_ptr) :: c_mpi_comm_f2c  ! MPI_Comm as pointer
-        end function c_mpi_comm_f2c
 
         function c_mpi_barrier(comm) bind(C, name="MPI_Barrier")
             use iso_c_binding, only: c_ptr, c_int
diff --git a/src/mpi_wrapper.c b/src/mpi_wrapper.c
index 8f0d80e..15084eb 100644
--- a/src/mpi_wrapper.c
+++ b/src/mpi_wrapper.c
@@ -32,11 +32,6 @@ MPI_Comm get_c_comm_from_fortran(int comm_f) {
     }
 }
 
-void mpi_comm_size_wrapper(int *comm_f, int *size, int *ierr) {
-    MPI_Comm comm = get_c_comm_from_fortran(*comm_f);
-    *ierr = MPI_Comm_size(comm, size);
-}
-
 void mpi_bcast_int_wrapper(int *buffer, int *count, int *datatype_f, int *root, int *comm_f, int *ierror) {
     MPI_Comm comm = get_c_comm_from_fortran(*comm_f);
     MPI_Datatype datatype;