diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index c2ebf9a38cb..e3f98455c37 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2011-06-30  Jason Merrill  <jason@redhat.com>
 
+	PR c++/49569
+	* method.c (implicitly_declare_fn): Set DECL_PARM_LEVEL and
+	DECL_PARM_INDEX on rhs parm.
+
 	* pt.c (iterative_hash_template_arg): Use cp_tree_operand_length.
 
 	PR c++/49355
diff --git a/gcc/cp/method.c b/gcc/cp/method.c
index f10e846d0ea..9b9eb9a9df9 100644
--- a/gcc/cp/method.c
+++ b/gcc/cp/method.c
@@ -1528,8 +1528,11 @@ implicitly_declare_fn (special_function_kind kind, tree type, bool const_p)
       /* Note that this parameter is *not* marked DECL_ARTIFICIAL; we
 	 want its type to be included in the mangled function
 	 name.  */
-      DECL_ARGUMENTS (fn) = cp_build_parm_decl (NULL_TREE, rhs_parm_type);
-      TREE_READONLY (DECL_ARGUMENTS (fn)) = 1;
+      tree decl = cp_build_parm_decl (NULL_TREE, rhs_parm_type);
+      TREE_READONLY (decl) = 1;
+      retrofit_lang_decl (decl);
+      DECL_PARM_INDEX (decl) = DECL_PARM_LEVEL (decl) = 1;
+      DECL_ARGUMENTS (fn) = decl;
     }
   /* Add the "this" parameter.  */
   this_parm = build_this_parm (fn_type, TYPE_UNQUALIFIED);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ed34b5f3c10..382e0981a70 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2011-06-30  Jason Merrill  <jason@redhat.com>
 
+	PR c++/49569
+	* g++.dg/cpp0x/regress/ctor1.C: New.
+
 	PR c++/49355
 	* g++.dg/cpp0x/initlist54.C: New.
 
diff --git a/gcc/testsuite/g++.dg/cpp0x/regress/ctor1.C b/gcc/testsuite/g++.dg/cpp0x/regress/ctor1.C
new file mode 100644
index 00000000000..c35d6011f3b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/regress/ctor1.C
@@ -0,0 +1,21 @@
+// PR c++/49569
+// { dg-options -std=c++0x }
+
+struct A
+{
+  virtual void f() = 0;
+};
+
+struct B: A
+{
+  int i;
+  virtual void f() { }
+};
+
+struct C
+{
+  B b;
+  C(): b() { }
+  C(const B& b): b(b) { }
+};
+