diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 94572cf4f48..25b34f21849 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,9 @@
+2010-07-12  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
+
+	PR fortran/37077
+	* trans-io.c (build_dt): Set common.unit to flag chracter(kind=4)
+	internal unit.
+
 2010-07-12  Mikael Morin  <mikael@gcc.gnu.org>
 
 	* expr.c (gfc_get_int_expr): Don't initialize mpfr data twice.
diff --git a/gcc/fortran/trans-io.c b/gcc/fortran/trans-io.c
index 8626e032da4..80cc765d134 100644
--- a/gcc/fortran/trans-io.c
+++ b/gcc/fortran/trans-io.c
@@ -1669,7 +1669,8 @@ build_dt (tree function, gfc_code * code)
 	{
 	  mask |= set_internal_unit (&block, &post_iu_block,
 				     var, dt->io_unit);
-	  set_parameter_const (&block, var, IOPARM_common_unit, 0);
+	  set_parameter_const (&block, var, IOPARM_common_unit,
+			       dt->io_unit->ts.kind == 1 ? 0 : -1);
 	}
     }
   else