diff --git a/model/src/w3iopomd.F90 b/model/src/w3iopomd.F90
index 4befb115d..9d178d750 100644
--- a/model/src/w3iopomd.F90
+++ b/model/src/w3iopomd.F90
@@ -1668,7 +1668,19 @@ SUBROUTINE W3IOPON_WRITE(timestep_only, IMOD, filename, ncerr)
 
   END SUBROUTINE W3IOPON_WRITE
 
-  !> Read/write point output in netCDF format.
+  !> Read or write the netCDF point output file,
+  !> depending on the value of the first parameter.
+  !>
+  !> When reading, the entire file is read with one call to this
+  !> subroutine.
+  !>
+  !> When writing, this subroutine can either write one timestep or
+  !> the whole model run. This is an option in the input file. If the
+  !> entire model run is to be written, then OFILES(2) is 0. If only
+  !> one timestep is to be written, then OFILES(2) is 1.
+  !>
+  !> If OFILES(2) is 0, the output file is names out_pnt.ww3. If
+  !> OFILES(2) is 1, the output file is named TIMETAG.out_pnt.ww3.
   !>
   !> @param[in] INXOUT String indicating read/write. Must be 'READ' or
   !> 'WRITE'.
diff --git a/regtests/unittests/test_io2.F90 b/regtests/unittests/test_io2.F90
index f35c99079..59fc82bd6 100644
--- a/regtests/unittests/test_io2.F90
+++ b/regtests/unittests/test_io2.F90
@@ -99,6 +99,7 @@ program test_io
   print *, 'testing writing the WW3 binary point file in netCDF...'
 
   ! Write in netCDF.
+  ofiles(2) = 1
   call w3iopon('WRITE', ndsop, iotest, imod)
   if (iotest .ne. 0) stop 100
   print *, 'OK!'