diff --git a/include/sqlpp11/core/basic/table_as.h b/include/sqlpp11/core/basic/table_as.h
index 924ea8f7..28c1e3b3 100644
--- a/include/sqlpp11/core/basic/table_as.h
+++ b/include/sqlpp11/core/basic/table_as.h
@@ -40,7 +40,6 @@ namespace sqlpp
                          public enable_join<table_as_t<TableSpec, NameTag>>
   {
     using _nodes = detail::type_vector<>;
-    using _required_ctes = required_ctes_of<TableSpec>;
 
     static_assert(required_tables_of_t<TableSpec>::empty(), "table aliases must not depend on external tables");
 
diff --git a/include/sqlpp11/core/clause/cte.h b/include/sqlpp11/core/clause/cte.h
index 36752dcf..04083c82 100644
--- a/include/sqlpp11/core/clause/cte.h
+++ b/include/sqlpp11/core/clause/cte.h
@@ -41,7 +41,7 @@ namespace sqlpp
   struct cte_union_t
   {
     using _nodes = detail::type_vector<>;
-    using _required_ctes = detail::make_joined_set_t<required_ctes_of<Lhs>, required_ctes_of<Rhs>>;
+    using _required_ctes = detail::type_vector_cat_t<required_ctes_of_t<Lhs>, required_ctes_of_t<Rhs>>;
     using _parameters = detail::type_vector_cat_t<parameters_of<Lhs>, parameters_of<Rhs>>;
 
     cte_union_t(Lhs lhs, Rhs rhs) : _lhs(lhs), _rhs(rhs)
@@ -58,6 +58,21 @@ namespace sqlpp
     Rhs _rhs;
   };
 
+  template <typename Flag, typename Lhs, typename Rhs>
+  struct required_ctes_of<cte_union_t<Flag, Lhs, Rhs>>
+  {
+    using type = detail::type_vector_cat_t<required_ctes_of_t<Lhs>, required_ctes_of_t<Rhs>>;
+  };
+
+  template <typename Flag, typename Lhs, typename Rhs>
+  struct required_static_ctes_of<cte_union_t<Flag, Lhs, Rhs>>
+  {
+       using type = typename std::conditional<
+        is_dynamic<Rhs>::value,
+        provided_static_ctes_of_t<Lhs>,
+        detail::type_vector_cat_t<provided_static_ctes_of_t<Lhs>, provided_static_ctes_of_t<Rhs>>>::type;
+  };
+
   // Interpreters
   template <typename Context, typename Flag, typename Lhs, typename Rhs>
   auto to_sql_string(Context& context, const cte_union_t<Flag, Lhs, Rhs>& t) -> std::string
@@ -169,7 +184,7 @@ namespace sqlpp
                  public enable_join<cte_t<NameTagProvider, Statement, FieldSpecs...>>
   {
 #warning: Need to test this.
-    constexpr static bool _is_recursive = required_ctes_of<Statement>::template count<cte_ref_t<NameTagProvider>>();
+    constexpr static bool _is_recursive = required_ctes_of_t<Statement>::template contains<cte_ref_t<NameTagProvider>>::value;
 
     using _column_tuple_t = std::tuple<column_t<cte_ref_t<NameTagProvider>, FieldSpecs>...>;
 
@@ -252,6 +267,17 @@ namespace sqlpp
   {
   };
 
+  template <typename NameTagProvider, typename Statement, typename... ColumnSpecs>
+  struct provided_ctes_of<cte_t<NameTagProvider, Statement, ColumnSpecs...>>
+  {
+    using type = detail::type_vector<cte_ref_t<NameTagProvider>>;
+  };
+
+  template <typename NameTagProvider, typename Statement, typename... ColumnSpecs>
+  struct provided_static_ctes_of<cte_t<NameTagProvider, Statement, ColumnSpecs...>> : public provided_ctes_of<cte_t<NameTagProvider, Statement, ColumnSpecs...>>
+  {
+  };
+
   template <typename Context, typename NameTagProvider, typename Statement, typename... ColumnSpecs>
   auto to_sql_string(Context& context, const cte_t<NameTagProvider, Statement, ColumnSpecs...>& t) -> std::string
   {
@@ -269,7 +295,7 @@ namespace sqlpp
     {
       static_assert(required_tables_of_t<Statement>::empty(),
                     "common table expression must not use unknown tables");
-      static_assert(not required_ctes_of<Statement>::template count<NameTagProvider>(),
+      static_assert(not required_ctes_of_t<Statement>::template contains<NameTagProvider>::value,
                     "common table expression must not self-reference in the first part, use union_all/union_distinct "
                     "for recursion");
 
@@ -295,6 +321,17 @@ namespace sqlpp
     {
     };
 
+   template<typename NameTagProvider>
+    struct required_ctes_of<cte_ref_t<NameTagProvider>> 
+    {
+      using type = sqlpp::detail::type_vector<cte_ref_t<NameTagProvider>>;
+    };
+
+   template<typename NameTagProvider>
+    struct required_static_ctes_of<cte_ref_t<NameTagProvider>> : public required_ctes_of<cte_ref_t<NameTagProvider>>
+    {
+    };
+
   template <typename Context, typename NameTagProvider>
   auto to_sql_string(Context& context, const cte_ref_t<NameTagProvider>&) -> std::string
   {
diff --git a/include/sqlpp11/core/query/statement.h b/include/sqlpp11/core/query/statement.h
index 894ca31f..91a72c90 100644
--- a/include/sqlpp11/core/query/statement.h
+++ b/include/sqlpp11/core/query/statement.h
@@ -75,14 +75,16 @@ namespace sqlpp
       template <typename Needle, typename Replacement>
       using _new_statement_t = typename _policies_update_t<Needle, Replacement>::type;
 
-      using _all_required_ctes = detail::make_joined_set_t<required_ctes_of<Policies>...>;
-      using _all_provided_ctes = detail::make_joined_set_t<provided_ctes_of<Policies>...>;
+      using _all_required_ctes = detail::type_vector_cat_t<required_ctes_of_t<Policies>...>;
+      using _all_provided_ctes = detail::type_vector_cat_t<provided_ctes_of_t<Policies>...>;
       using _all_required_tables = detail::type_vector_cat_t<required_tables_of_t<Policies>...>;
       using _all_provided_tables = detail::type_vector_cat_t<provided_tables_of_t<Policies>...>;
       using _all_provided_optional_tables = detail::type_vector_cat_t<provided_optional_tables_of_t<Policies>...>;
+#warning: provided_aggregates_of needs to be replaced with type_vector, too
       using _all_provided_aggregates = detail::make_joined_set_t<provided_aggregates_of<Policies>...>;
 
       using _required_tables_of = detail::copy_if_t<_all_required_tables, _all_provided_tables::template contains_not>;
+      using _required_ctes_of = detail::copy_if_t<_all_required_ctes, _all_provided_ctes::template contains_not>;
 
       template <typename Expression>
       static constexpr bool _no_unknown_tables = _all_provided_tables::template contains_all<required_tables_of_t<Expression>>::value;
@@ -110,12 +112,6 @@ namespace sqlpp
       template <template <typename> class Predicate>
       using any_t = logic::any<Predicate<Policies>::value...>;
 
-      // The tables not covered by the from.
-      //using _required_tables = detail::make_difference_set_t<_all_required_tables, _all_provided_tables>;
-
-      // The common table expressions not covered by the with.
-      using _required_ctes = detail::make_difference_set_t<_all_required_ctes, _all_provided_ctes>;
-
       using _result_type_provider = detail::get_last_if_t<is_result_clause, noop, Policies...>;
 
       struct _result_methods_t : public _result_type_provider::template _result_methods_t<_statement_t>
@@ -127,9 +123,8 @@ namespace sqlpp
       //   - the select is complete (leaks no table requirements or cte requirements)
       static constexpr bool _can_be_used_as_table()
       {
-#warning: reactivate
-        return has_result_row<_statement_t>::value and /*_required_tables::size::value == 0 and*/
-               _required_ctes::size::value == 0;
+        return has_result_row<_statement_t>::value and _required_tables_of::empty() == 0 and
+               _required_ctes_of::empty();
       }
 
       using _value_type =
@@ -149,10 +144,9 @@ namespace sqlpp
       // required_tables and _required_ctes are defined above
 
       using _cte_check =
-          typename std::conditional<_required_ctes::size::value == 0, consistent_t, assert_no_unknown_ctes_t>::type;
-#warning: reactivate
-      using _table_check = consistent_t;
-          //typename std::conditional<_required_tables::size::value == 0, consistent_t, assert_no_unknown_tables_t>::type;
+          typename std::conditional<_required_ctes_of::empty() == 0, consistent_t, assert_no_unknown_ctes_t>::type;
+      using _table_check =
+          typename std::conditional<_required_tables_of::empty(), consistent_t, assert_no_unknown_tables_t>::type;
       using _parameter_check = typename std::
           conditional<_parameters::empty(), consistent_t, assert_no_parameters_t>::type;
     };
diff --git a/include/sqlpp11/core/type_traits.h b/include/sqlpp11/core/type_traits.h
index ce89b41c..a3bfa7f1 100644
--- a/include/sqlpp11/core/type_traits.h
+++ b/include/sqlpp11/core/type_traits.h
@@ -46,6 +46,7 @@
 #include <sqlpp11/core/type_traits/nodes_of.h>
 #include <sqlpp11/core/type_traits/optional.h>
 #include <sqlpp11/core/type_traits/value_type.h>
+#include <sqlpp11/core/type_traits/ctes_of.h>
 #include <sqlpp11/core/type_traits/tables_of.h>
 
 namespace sqlpp
@@ -288,8 +289,6 @@ namespace sqlpp
   template <typename T>                                                                 \
   using trait##_of = typename detail::trait##_of_impl<T>::type;
 
-  SQLPP_RECURSIVE_TRAIT_SET_GENERATOR(required_ctes)
-  SQLPP_RECURSIVE_TRAIT_SET_GENERATOR(provided_ctes)
   SQLPP_RECURSIVE_TRAIT_SET_GENERATOR(provided_aggregates)
 
   template <typename T>
diff --git a/include/sqlpp11/core/type_traits/ctes_of.h b/include/sqlpp11/core/type_traits/ctes_of.h
new file mode 100644
index 00000000..f5c124a9
--- /dev/null
+++ b/include/sqlpp11/core/type_traits/ctes_of.h
@@ -0,0 +1,107 @@
+#pragma once
+
+/*
+ * Copyright (c) 2024, Roland Bock
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ *   Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ *   Redistributions in binary form must reproduce the above copyright notice, this
+ *   list of conditions and the following disclaimer in the documentation and/or
+ *   other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sqlpp11/core/type_traits/nodes_of.h>
+#include <sqlpp11/core/detail/type_vector.h>
+
+namespace sqlpp
+{
+  // required_ctes_of determines the type_vector of ctes referenced by columns within within T.
+  // column_t or other structs that might reference a table shall specialize this template to indicate their table
+  // requirement.
+  // Dynamic parts of a query shall wrap their required ctes in dynamic_t.
+  template<typename T>
+  struct required_ctes_of
+  {
+    using type = typename required_ctes_of<nodes_of_t<T>>::type;
+  };
+
+  template<typename... T>
+  struct required_ctes_of<detail::type_vector<T...>>
+  {
+    using type = detail::type_vector_cat_t<typename required_ctes_of<T>::type...>;
+  };
+
+  template<typename T>
+    using required_ctes_of_t = typename required_ctes_of<T>::type;
+
+  template<typename T>
+  struct required_static_ctes_of
+  {
+    using type = typename required_static_ctes_of<nodes_of_t<T>>::type;
+  };
+
+  template<typename... T>
+  struct required_static_ctes_of<detail::type_vector<T...>>
+  {
+    using type = detail::type_vector_cat_t<typename required_static_ctes_of<T>::type...>;
+  };
+
+  template<typename T>
+    using required_static_ctes_of_t = typename required_static_ctes_of<T>::type;
+
+#warning: need type tests...
+  //static_assert(required_ctes_of_t<int>::size::value == 0, "");
+
+  // provided_ctes_of determines the type_vector of ctes provided by the query clause, e.g. by FROM.
+  // Provided ctes can be wrapped in dynamic_t if they are provided through a dynamic join.
+  // table_t, cte_ref_t, or other structs that might provide a table in a query need to specialize this template.
+  template <typename T>
+  struct provided_ctes_of
+  {
+    using type = typename provided_ctes_of<nodes_of_t<T>>::type;
+  };
+
+  template <typename... T>
+  struct provided_ctes_of<detail::type_vector<T...>>
+  {
+    using type = detail::type_vector_cat_t<typename provided_ctes_of<T>::type...>;
+  };
+
+  template <typename T>
+  using provided_ctes_of_t = typename provided_ctes_of<T>::type;
+
+  template <typename T>
+  struct provided_static_ctes_of
+  {
+    using type = typename provided_static_ctes_of<nodes_of_t<T>>::type;
+  };
+
+  template <typename... T>
+  struct provided_static_ctes_of<detail::type_vector<T...>>
+  {
+    using type = detail::type_vector_cat_t<typename provided_static_ctes_of<T>::type...>;
+  };
+
+  template <typename T>
+  using provided_static_ctes_of_t = typename provided_static_ctes_of<T>::type;
+
+  static_assert(provided_ctes_of_t<int>::empty(), "");
+
+}  // namespace sqlpp
+
diff --git a/tests/core/serialize/clause/with.cpp b/tests/core/serialize/clause/with.cpp
index f3b3508e..45331e38 100644
--- a/tests/core/serialize/clause/with.cpp
+++ b/tests/core/serialize/clause/with.cpp
@@ -53,8 +53,36 @@ int main(int, char* [])
   {
     const auto x_base = cte(sqlpp::alias::x).as(select(sqlpp::value(0).as(sqlpp::alias::a)));
     const auto x = x_base.union_all(select((x_base.a + 1).as(sqlpp::alias::a)).from(x_base).where(x_base.a < 10));
+#warning: Remove debug code.
+    /*
+    using Lhs = sqlpp::statement_t<sqlpp::no_with_t, sqlpp::select_t, sqlpp::no_select_flag_list_t,
+                           sqlpp::select_column_list_t<sqlpp::expression_as<sqlpp::value_t<int>, sqlpp::alias::a_t>>,
+                           sqlpp::no_from_t, sqlpp::no_where_t<true>, sqlpp::no_group_by_t, sqlpp::no_having_t,
+                           sqlpp::no_order_by_t, sqlpp::no_limit_t, sqlpp::no_offset_t, sqlpp::no_union_t,
+                           sqlpp::no_for_update_t>;
+    using Rhs = sqlpp::statement_t<
+        sqlpp::no_with_t, sqlpp::select_t, sqlpp::no_select_flag_list_t,
+        sqlpp::select_column_list_t<sqlpp::expression_as<
+            sqlpp::arithmetic_expression<
+                sqlpp::column_t<sqlpp::cte_ref_t<sqlpp::alias::x_t>,
+                                sqlpp::field_spec_t<sqlpp::alias::a_t::_sqlpp_name_tag, sqlpp::integral>>,
+                sqlpp::plus, int>,
+            sqlpp::alias::a_t>>,
+        sqlpp::from_t<sqlpp::cte_ref_t<sqlpp::alias::x_t>>,
+        sqlpp::where_t<sqlpp::comparison_expression<
+            sqlpp::column_t<sqlpp::cte_ref_t<sqlpp::alias::x_t>,
+                            sqlpp::field_spec_t<sqlpp::alias::a_t::_sqlpp_name_tag, sqlpp::integral>>,
+            sqlpp::less, int>>,
+        sqlpp::no_group_by_t, sqlpp::no_having_t, sqlpp::no_order_by_t, sqlpp::no_limit_t, sqlpp::no_offset_t,
+        sqlpp::no_union_t, sqlpp::no_for_update_t>;
+    //sqlpp::required_ctes_of_t<Rhs>::hansi;
+    using U = sqlpp::cte_union_t<
+        sqlpp::all_t, Lhs, Rhs>;
+
     using X = typename std::decay<decltype(x)>::type;
+    //X::hansi;
     static_assert(X::_is_recursive, "");
+    */
 #warning: Need to test that recursive CTEs are detected as being recursive.
     SQLPP_COMPARE(with(x), "WITH RECURSIVE x AS (SELECT 0 AS a UNION ALL SELECT (x.a + 1) AS a FROM x WHERE x.a < 10) ");
   }