diff --git a/src/core/MOM_open_boundary.F90 b/src/core/MOM_open_boundary.F90
index 7bfb6479b2..b54c93cefa 100644
--- a/src/core/MOM_open_boundary.F90
+++ b/src/core/MOM_open_boundary.F90
@@ -854,7 +854,7 @@ subroutine initialize_segment_data(G, GV, US, OBC, PF)
 !       if (siz(4) == 1) segment%values_needed = .false.
         if (segment%on_pe) then
           if (OBC%brushcutter_mode .and. (modulo(siz(1),2) == 0 .or. modulo(siz(2),2) == 0)) then
-            write(mesg,'("Brushcutter mode sizes ", I6, I6))') siz(1), siz(2)
+            write(mesg,'("Brushcutter mode sizes ", I6, I6)') siz(1), siz(2)
             call MOM_error(WARNING, mesg // " " // trim(filename) // " " // trim(fieldname))
             call MOM_error(FATAL,'segment data are not on the supergrid')
           endif