diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 3510512d751..ea9cbb775e6 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -2206,6 +2206,10 @@ enum languages { lang_c, lang_cplusplus };
 #define NON_UNION_CLASS_TYPE_P(T) \
   (TREE_CODE (T) == RECORD_TYPE && TYPE_LANG_FLAG_5 (T))
 
+/* Nonzero if T is a class type and is a union.  */
+#define UNION_CLASS_TYPE_P(T) \
+  (TREE_CODE (T) == UNION_TYPE && TYPE_LANG_FLAG_5 (T))
+
 /* Keep these checks in ascending code order.  */
 #define RECORD_OR_UNION_CODE_P(T)	\
   ((T) == RECORD_TYPE || (T) == UNION_TYPE)
@@ -4184,11 +4188,14 @@ more_aggr_init_expr_args_p (const aggr_init_expr_arg_iterator *iter)
 #define TYPENAME_IS_ENUM_P(NODE) \
   (TREE_LANG_FLAG_0 (TYPENAME_TYPE_CHECK (NODE)))
 
-/* True if a TYPENAME_TYPE was declared as a "class", "struct", or
-   "union".  */
+/* True if a TYPENAME_TYPE was declared as a "class", "struct".  */
 #define TYPENAME_IS_CLASS_P(NODE) \
   (TREE_LANG_FLAG_1 (TYPENAME_TYPE_CHECK (NODE)))
 
+/* True if a TYPENAME_TYPE was declared as an "union".  */
+#define TYPENAME_IS_UNION_P(NODE) \
+  (TREE_LANG_FLAG_3 (TYPENAME_TYPE_CHECK (NODE)))
+
 /* True if a TYPENAME_TYPE is in the process of being resolved.  */
 #define TYPENAME_IS_RESOLVING_P(NODE) \
   (TREE_LANG_FLAG_2 (TYPENAME_TYPE_CHECK (NODE)))
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 56f80775ca0..8fa07e30d69 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -3930,6 +3930,7 @@ struct typename_info {
   tree template_id;
   bool enum_p;
   bool class_p;
+  bool union_p;
 };
 
 struct typename_hasher : ggc_ptr_hash<tree_node>
@@ -3958,7 +3959,8 @@ struct typename_hasher : ggc_ptr_hash<tree_node>
 	    && TYPE_CONTEXT (t1) == t2->scope
 	    && TYPENAME_TYPE_FULLNAME (t1) == t2->template_id
 	    && TYPENAME_IS_ENUM_P (t1) == t2->enum_p
-	    && TYPENAME_IS_CLASS_P (t1) == t2->class_p);
+	    && TYPENAME_IS_CLASS_P (t1) == t2->class_p
+	    && TYPENAME_IS_UNION_P (t1) == t2->union_p);
   }
 };
 
@@ -3983,8 +3985,8 @@ build_typename_type (tree context, tree name, tree fullname,
   ti.template_id = fullname;
   ti.enum_p = tag_type == enum_type;
   ti.class_p = (tag_type == class_type
-		|| tag_type == record_type
-		|| tag_type == union_type);
+		|| tag_type == record_type);
+  ti.union_p = tag_type == union_type;
   hashval_t hash =  (htab_hash_pointer (ti.scope)
 		     ^ htab_hash_pointer (ti.name));
 
@@ -4001,6 +4003,7 @@ build_typename_type (tree context, tree name, tree fullname,
       TYPENAME_TYPE_FULLNAME (t) = ti.template_id;
       TYPENAME_IS_ENUM_P (t) = ti.enum_p;
       TYPENAME_IS_CLASS_P (t) = ti.class_p;
+      TYPENAME_IS_UNION_P (t) = ti.union_p;
 
       /* Build the corresponding TYPE_DECL.  */
       tree d = build_decl (input_location, TYPE_DECL, name, t);
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index daea3b39a15..49b509eef14 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -671,6 +671,7 @@ dump_type (cxx_pretty_printer *pp, tree t, int flags)
       pp_cxx_ws_string (pp,
 			 TYPENAME_IS_ENUM_P (t) ? "enum"
 			 : TYPENAME_IS_CLASS_P (t) ? "class"
+			 : TYPENAME_IS_UNION_P (t) ? "union"
 			 : "typename");
       dump_typename (pp, t, flags);
       break;
diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 71d0fab411f..f956d1d90cb 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -8819,6 +8819,8 @@ trees_out::type_node (tree type)
 	      tag_type = enum_type;
 	    else if (TYPENAME_IS_CLASS_P (type))
 	      tag_type = class_type;
+	    else if (TYPENAME_IS_UNION_P (type))
+	      tag_type = union_type;
 	    u (int (tag_type));
 	  }
 	}
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 55e6a1a8b3a..bbb1a52e381 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -33304,7 +33304,9 @@ cp_parser_check_class_key (cp_parser *parser, location_t key_loc,
     return;
 
   bool seen_as_union = TREE_CODE (type) == UNION_TYPE;
-  if (seen_as_union != (class_key == union_type))
+  if (class_key != typename_type
+      && TREE_CODE (type) != TYPENAME_TYPE
+      && seen_as_union != (class_key == union_type))
     {
       if (permerror (input_location, "%qs tag used in naming %q#T",
 		     class_key == union_type ? "union"
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index d3efc6ea238..3d7539f62c1 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -16113,7 +16113,7 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 		else
 		  return error_mark_node;
 	      }
-	    else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
+	    else if (TYPENAME_IS_CLASS_P (t) && !NON_UNION_CLASS_TYPE_P (f))
 	      {
 		if (complain & tf_error)
 		  error ("%qT resolves to %qT, which is not a class type",
@@ -16121,6 +16121,14 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 		else
 		  return error_mark_node;
 	      }
+	    else if (TYPENAME_IS_UNION_P (t) && !UNION_CLASS_TYPE_P (f))
+	      {
+		if (complain & tf_error)
+		  error ("%qT resolves to %qT, which is not an union type",
+			 t, f);
+		else
+		  return error_mark_node;
+	      }
 	  }
 
 	return cp_build_qualified_type_real
diff --git a/gcc/testsuite/g++.dg/pr83469-1.C b/gcc/testsuite/g++.dg/pr83469-1.C
new file mode 100644
index 00000000000..94a21fbbb98
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr83469-1.C
@@ -0,0 +1,15 @@
+// { dg-do compile }
+// PR C++/83469
+    struct S {
+        union U { int m; };
+    };
+
+    template <typename T>
+      void f()
+      { union T::U u; }
+
+    int
+    main()
+    {
+      f<S>();
+    }
diff --git a/gcc/testsuite/g++.dg/pr83469-2.C b/gcc/testsuite/g++.dg/pr83469-2.C
new file mode 100644
index 00000000000..c202e36b03b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr83469-2.C
@@ -0,0 +1,13 @@
+// { dg-do compile }
+// PR C++/83469
+    struct S {
+        union U { int m; };
+    };
+    template <typename T>
+      void f()
+      { struct T::U u; } // { dg-error "" }
+    int
+    main()
+    {
+      f<S>();
+    }
diff --git a/gcc/testsuite/g++.dg/pr83469-3.C b/gcc/testsuite/g++.dg/pr83469-3.C
new file mode 100644
index 00000000000..1ffff0af3c9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr83469-3.C
@@ -0,0 +1,13 @@
+// { dg-do compile }
+// PR C++/83469
+    struct S {
+        struct C { int m; };
+    };
+    template <typename T>
+      void f()
+      { union T::C u; } // { dg-error "" }
+    int
+    main()
+    {
+      f<S>();
+    }
diff --git a/gcc/testsuite/g++.dg/pr93809-1.C b/gcc/testsuite/g++.dg/pr93809-1.C
new file mode 100644
index 00000000000..321ea517cbf
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr93809-1.C
@@ -0,0 +1,11 @@
+// { dg-do compile }
+// PR C++/93809
+class C { };
+enum E { };
+struct S { };
+union U { };
+
+typedef typename ::C C2;
+typedef typename ::E E2;
+typedef typename ::S S2;
+typedef typename ::U U2;   // error
diff --git a/gcc/testsuite/g++.dg/pr93809-2.C b/gcc/testsuite/g++.dg/pr93809-2.C
new file mode 100644
index 00000000000..a98dada30ee
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr93809-2.C
@@ -0,0 +1,5 @@
+// { dg-do compile }
+// { dg-require-effective-target c++11 }
+// PR C++/93809
+union a{};
+auto var = new (typename :: a );
diff --git a/gcc/testsuite/g++.dg/pr93809-3.C b/gcc/testsuite/g++.dg/pr93809-3.C
new file mode 100644
index 00000000000..f544b1f059f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr93809-3.C
@@ -0,0 +1,4 @@
+// { dg-do compile }
+// PR C++/93809
+typedef union{} typedef_union;
+typename :: typedef_union foo1 () { return typedef_union();  } 
diff --git a/gcc/testsuite/g++.dg/warn/Wredundant-tags-3.C b/gcc/testsuite/g++.dg/warn/Wredundant-tags-3.C
index 0eeee34dae7..dcccdcad22d 100644
--- a/gcc/testsuite/g++.dg/warn/Wredundant-tags-3.C
+++ b/gcc/testsuite/g++.dg/warn/Wredundant-tags-3.C
@@ -28,7 +28,7 @@ struct N::S s3;       // { dg-warning "-Wredundant-tags" }
 
 N::U u1;
 typename N::U u2;     // { dg-bogus "-Wredundant-tags" }
-                      // { dg-bogus "'class' tag used in naming 'union N::U" "pr93809" { xfail *-*-*} .-1 }
+                      // { dg-bogus "'class' tag used in naming 'union N::U" "pr93809" { target *-*-*} .-1 }
 union N::U u3;        // { dg-warning "-Wredundant-tags" }