Index: gcc/testsuite/gfortran.dg/typebound_operator_2.f03
===================================================================
--- gcc/testsuite/gfortran.dg/typebound_operator_2.f03	(Revision 152915)
+++ gcc/testsuite/gfortran.dg/typebound_operator_2.f03	(Arbeitskopie)
@@ -50,7 +50,6 @@ CONTAINS
   LOGICAL FUNCTION func (me, b) ! { dg-error "must be a SUBROUTINE" }
     CLASS(t), INTENT(OUT) :: me
     CLASS(t), INTENT(IN) :: b
-    me = t ()
     func = .TRUE.
   END FUNCTION func
 
Index: gcc/testsuite/gfortran.dg/typebound_operator_4.f03
===================================================================
--- gcc/testsuite/gfortran.dg/typebound_operator_4.f03	(Revision 152915)
+++ gcc/testsuite/gfortran.dg/typebound_operator_4.f03	(Arbeitskopie)
@@ -37,7 +37,7 @@ CONTAINS
   PURE SUBROUTINE assign_int (dest, from)
     CLASS(myint), INTENT(OUT) :: dest
     INTEGER, INTENT(IN) :: from
-    dest = myint (from)
+    dest%value = from
   END SUBROUTINE assign_int
 
   TYPE(myreal) FUNCTION add_real (a, b)
@@ -49,7 +49,7 @@ CONTAINS
   SUBROUTINE assign_real (dest, from)
     CLASS(myreal), INTENT(OUT) :: dest
     REAL, INTENT(IN) :: from
-    dest = myreal (from)
+    dest%value = from
   END SUBROUTINE assign_real
 
   SUBROUTINE in_module ()
Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c	(Revision 152915)
+++ gcc/fortran/resolve.c	(Arbeitskopie)
@@ -7629,6 +7629,14 @@ resolve_ordinary_assign (gfc_code *code, gfc_names
 	}
     }
 
+  /* F03:7.4.1.2.  */
+  if (lhs->ts.type == BT_CLASS)
+    {
+      gfc_error ("Variable must not be polymorphic in assignment at %L",
+		 &lhs->where);
+      return false;
+    }
+
   gfc_check_assign (lhs, rhs, 1);
   return false;
 }