diff --git a/include/rfl/internal/all_fields.hpp b/include/rfl/internal/all_fields.hpp
index 9d9190b1..4e63b0f3 100644
--- a/include/rfl/internal/all_fields.hpp
+++ b/include/rfl/internal/all_fields.hpp
@@ -1,23 +1,13 @@
 #ifndef RFL_INTERNAL_ALLFIELDS_HPP_
 #define RFL_INTERNAL_ALLFIELDS_HPP_
 
-#include "../Tuple.hpp"
 #include "is_field.hpp"
 
-namespace rfl {
-namespace internal {
+namespace rfl::internal {
 
-template <class TupleType, int _i = 0>
-constexpr bool all_fields() {
-  if constexpr (_i == rfl::tuple_size_v<TupleType>) {
-    return true;
-  } else {
-    using T = tuple_element_t<_i, TupleType>;
-    return is_field_v<T> && all_fields<TupleType, _i + 1>();
-  }
-}
+template <class... Ts>
+constexpr bool all_fields_v = (is_field_v<Ts> && ...);
 
-}  // namespace internal
-}  // namespace rfl
+}  // namespace rfl::internal
 
 #endif
diff --git a/include/rfl/internal/is_field.hpp b/include/rfl/internal/is_field.hpp
index 4a210814..e8f1b815 100644
--- a/include/rfl/internal/is_field.hpp
+++ b/include/rfl/internal/is_field.hpp
@@ -6,8 +6,7 @@
 #include "../Field.hpp"
 #include "StringLiteral.hpp"
 
-namespace rfl {
-namespace internal {
+namespace rfl::internal {
 
 template <class T>
 class is_field;
@@ -22,7 +21,6 @@ template <class T>
 constexpr bool is_field_v =
     is_field<std::remove_cvref_t<std::remove_pointer_t<T>>>::value;
 
-}  // namespace internal
-}  // namespace rfl
+}  // namespace rfl::internal
 
 #endif
diff --git a/include/rfl/parsing/FieldVariantParser.hpp b/include/rfl/parsing/FieldVariantParser.hpp
index 8b68f68d..ea455695 100644
--- a/include/rfl/parsing/FieldVariantParser.hpp
+++ b/include/rfl/parsing/FieldVariantParser.hpp
@@ -5,17 +5,18 @@
 #include <string>
 #include <type_traits>
 
+#include "../NamedTuple.hpp"
 #include "../Result.hpp"
 #include "../Tuple.hpp"
 #include "../Variant.hpp"
-#include "../always_false.hpp"
-#include "../visit.hpp"
+#include "../internal/no_duplicate_field_names.hpp"
+#include "../internal/to_ptr_field.hpp"
+#include "../make_named_tuple.hpp"
 #include "FieldVariantReader.hpp"
 #include "Parser_base.hpp"
 #include "schema/Type.hpp"
 
-namespace rfl {
-namespace parsing {
+namespace rfl::parsing {
 
 /// To be used when all options of the variants are rfl::Field. Essentially,
 /// this is an externally tagged union.
@@ -93,13 +94,21 @@ struct FieldVariantParser {
    * @return The schema type.
    */
   static schema::Type to_schema(
-      std::map<std::string, schema::Type>* _definitions,
-      std::vector<schema::Type> = {}) {
-    using VariantType = rfl::Variant<NamedTuple<FieldTypes>...>;
-    return Parser<R, W, VariantType, ProcessorsType>::to_schema(_definitions);
+      std::map<std::string, schema::Type>* _definitions) {
+    return schema::Type{schema::Type::AnyOf{
+        .types_ = std::vector<schema::Type>(
+            {one_field_to_type<FieldTypes>(_definitions)...})}};
+  }
+
+ private:
+  template <class FieldType>
+  static schema::Type one_field_to_type(
+      std::map<std::string, schema::Type>* _definitions) noexcept {
+    using NamedTupleType = NamedTuple<std::remove_cvref_t<FieldType>>;
+    return Parser<R, W, NamedTupleType, ProcessorsType>::to_schema(
+        _definitions);
   }
 };
-}  // namespace parsing
-}  // namespace rfl
+}  // namespace rfl::parsing
 
 #endif
diff --git a/include/rfl/parsing/ParserRflVariant.hpp b/include/rfl/parsing/ParserRflVariant.hpp
index 744764ff..3b90b173 100644
--- a/include/rfl/parsing/ParserRflVariant.hpp
+++ b/include/rfl/parsing/ParserRflVariant.hpp
@@ -6,10 +6,10 @@
 
 #include "../Result.hpp"
 #include "../Variant.hpp"
-#include "../always_false.hpp"
 #include "../internal/add_tags_to_variants_v.hpp"
 #include "../internal/all_fields.hpp"
 #include "../internal/nth_element_t.hpp"
+#include "../visit.hpp"
 #include "FieldVariantParser.hpp"
 #include "Parent.hpp"
 #include "Parser_base.hpp"
@@ -52,7 +52,7 @@ class ParserRflVariant<R, W, rfl::Variant<AlternativeTypes...>,
    */
   static Result<rfl::Variant<AlternativeTypes...>> read(
       const R& _r, const InputVarType& _var) noexcept {
-    if constexpr (internal::all_fields<std::tuple<AlternativeTypes...>>()) {
+    if constexpr (internal::all_fields_v<AlternativeTypes...>) {
       if constexpr (schemaful::IsSchemafulReader<R>) {
         using WrappedType = rfl::Variant<NamedTuple<AlternativeTypes>...>;
         return Parser<R, W, WrappedType, ProcessorsType>::read(_r, _var)
@@ -124,7 +124,7 @@ class ParserRflVariant<R, W, rfl::Variant<AlternativeTypes...>,
   static void write(const W& _w,
                     const rfl::Variant<AlternativeTypes...>& _variant,
                     const P& _parent) {
-    if constexpr (internal::all_fields<std::tuple<AlternativeTypes...>>()) {
+    if constexpr (internal::all_fields_v<AlternativeTypes...>) {
       if constexpr (schemaful::IsSchemafulWriter<W>) {
         using WrappedType = rfl::Variant<
             NamedTuple<Field<AlternativeTypes::name_,
@@ -186,7 +186,7 @@ class ParserRflVariant<R, W, rfl::Variant<AlternativeTypes...>,
    */
   static schema::Type to_schema(
       std::map<std::string, schema::Type>* _definitions) {
-    if constexpr (internal::all_fields<std::tuple<AlternativeTypes...>>()) {
+    if constexpr (internal::all_fields_v<AlternativeTypes...>) {
       return FieldVariantParser<R, W, ProcessorsType,
                                 AlternativeTypes...>::to_schema(_definitions);
 
@@ -201,29 +201,18 @@ class ParserRflVariant<R, W, rfl::Variant<AlternativeTypes...>,
           _definitions);
 
     } else {
-      std::vector<schema::Type> types;
-      build_schema(
-          _definitions, &types,
-          std::make_integer_sequence<int, sizeof...(AlternativeTypes)>());
-      return schema::Type{schema::Type::AnyOf{.types_ = std::move(types)}};
+      return schema::Type{schema::Type::AnyOf{
+          .types_ = std::vector<schema::Type>(
+              {one_field_to_type<AlternativeTypes>(_definitions)...})}};
     }
   }
 
  private:
-  template <size_t _i>
-  static void add_to_schema(std::map<std::string, schema::Type>* _definitions,
-                            std::vector<schema::Type>* _types) noexcept {
-    using AltType =
-        std::remove_cvref_t<internal::nth_element_t<_i, AlternativeTypes...>>;
-    _types->push_back(
-        Parser<R, W, AltType, ProcessorsType>::to_schema(_definitions));
-  }
-
-  template <int... _is>
-  static void build_schema(std::map<std::string, schema::Type>* _definitions,
-                           std::vector<schema::Type>* _types,
-                           std::integer_sequence<int, _is...>) noexcept {
-    (add_to_schema<_is>(_definitions, _types), ...);
+  template <class AltType>
+  static schema::Type one_field_to_type(
+      std::map<std::string, schema::Type>* _definitions) noexcept {
+    return Parser<R, W, std::remove_cvref_t<AltType>,
+                  ProcessorsType>::to_schema(_definitions);
   }
 
   template <int _i>
diff --git a/include/rfl/parsing/ParserVariant.hpp b/include/rfl/parsing/ParserVariant.hpp
index 61eff403..0fe1e707 100644
--- a/include/rfl/parsing/ParserVariant.hpp
+++ b/include/rfl/parsing/ParserVariant.hpp
@@ -7,13 +7,12 @@
 #include <variant>
 
 #include "../NamedTuple.hpp"
-#include "../Ref.hpp"
 #include "../Result.hpp"
 #include "../Variant.hpp"
-#include "../always_false.hpp"
 #include "../internal/add_tags_to_variants_v.hpp"
 #include "../internal/all_fields.hpp"
 #include "../internal/to_ptr_field.hpp"
+#include "../visit.hpp"
 #include "FieldVariantParser.hpp"
 #include "Parent.hpp"
 #include "Parser_base.hpp"
@@ -66,7 +65,7 @@ class ParserVariant<R, W, std::variant<AlternativeTypes...>, ProcessorsType> {
    */
   static Result<std::variant<AlternativeTypes...>> read(
       const R& _r, const InputVarType& _var) noexcept {
-    if constexpr (internal::all_fields<std::tuple<AlternativeTypes...>>()) {
+    if constexpr (internal::all_fields_v<AlternativeTypes...>) {
       if constexpr (schemaful::IsSchemafulReader<R>) {
         using WrappedType = rfl::Variant<NamedTuple<AlternativeTypes>...>;
         return Parser<R, W, WrappedType, ProcessorsType>::read(_r, _var)
@@ -146,7 +145,7 @@ class ParserVariant<R, W, std::variant<AlternativeTypes...>, ProcessorsType> {
   static void write(const W& _w,
                     const std::variant<AlternativeTypes...>& _variant,
                     const P& _parent) {
-    if constexpr (internal::all_fields<std::tuple<AlternativeTypes...>>()) {
+    if constexpr (internal::all_fields_v<AlternativeTypes...>) {
       if constexpr (schemaful::IsSchemafulWriter<W>) {
         using WrappedType = rfl::Variant<
             NamedTuple<Field<AlternativeTypes::name_,
@@ -220,7 +219,7 @@ class ParserVariant<R, W, std::variant<AlternativeTypes...>, ProcessorsType> {
    */
   static schema::Type to_schema(
       std::map<std::string, schema::Type>* _definitions) {
-    if constexpr (internal::all_fields<std::tuple<AlternativeTypes...>>()) {
+    if constexpr (internal::all_fields_v<AlternativeTypes...>) {
       return FieldVariantParser<R, W, ProcessorsType,
                                 AlternativeTypes...>::to_schema(_definitions);
 
@@ -235,42 +234,18 @@ class ParserVariant<R, W, std::variant<AlternativeTypes...>, ProcessorsType> {
           _definitions);
 
     } else {
-      std::vector<schema::Type> types;
-      build_schema(
-          _definitions, &types,
-          std::make_integer_sequence<int, sizeof...(AlternativeTypes)>());
-      return schema::Type{schema::Type::AnyOf{.types_ = std::move(types)}};
+      return schema::Type{schema::Type::AnyOf{
+          .types_ = std::vector<schema::Type>(
+              {one_field_to_type<AlternativeTypes>(_definitions)...})}};
     }
   }
 
  private:
-  /**
-   * @brief Adds an alternative to the schema.
-   *
-   * @tparam _i The index of the alternative.
-   * @param _definitions The map of definitions to add the schema to.
-   * @param _types The vector of types to add the generated schema to.
-   */
-  template <size_t _i>
-  static void add_to_schema(std::map<std::string, schema::Type>* _definitions,
-                            std::vector<schema::Type>* _types) noexcept {
-    using U = std::remove_cvref_t<
-        std::variant_alternative_t<_i, std::variant<AlternativeTypes...>>>;
-    _types->push_back(Parser<R, W, U, ProcessorsType>::to_schema(_definitions));
-  }
-
-  /**
-   * @brief Builds the schema for the variant.
-   *
-   * @tparam _is The indices of the alternatives.
-   * @param _definitions The map of definitions to add the schema to.
-   * @param _types The vector of types to add the generated schemas to.
-   */
-  template <int... _is>
-  static void build_schema(std::map<std::string, schema::Type>* _definitions,
-                           std::vector<schema::Type>* _types,
-                           std::integer_sequence<int, _is...>) noexcept {
-    (add_to_schema<_is>(_definitions, _types), ...);
+  template <class AltType>
+  static schema::Type one_field_to_type(
+      std::map<std::string, schema::Type>* _definitions) noexcept {
+    return Parser<R, W, std::remove_cvref_t<AltType>,
+                  ProcessorsType>::to_schema(_definitions);
   }
 
   /**
diff --git a/tests/json/test_json_schema7.cpp b/tests/json/test_json_schema7.cpp
new file mode 100644
index 00000000..f75443ea
--- /dev/null
+++ b/tests/json/test_json_schema7.cpp
@@ -0,0 +1,26 @@
+#include <rfl.hpp>
+#include <rfl/json.hpp>
+
+namespace test_json_schema7 {
+
+struct Circle {
+  double radius;
+};
+struct Rectangle {
+  double height;
+  double width;
+};
+
+using Shapes = rfl::Variant<Circle, Rectangle>;
+
+TEST(json, test_json_schema7) {
+  const Shapes r = Rectangle{.height = 10, .width = 5};
+
+  const auto json_schema =
+      rfl::json::to_schema<Shapes, rfl::AddTagsToVariants>();
+
+  ASSERT_EQ(
+      json_schema,
+      R"({"$schema":"https://json-schema.org/draft/2020-12/schema","anyOf":[{"type":"object","properties":{"Circle":{"$ref":"#/$defs/test_json_schema7__Circle"}},"required":["Circle"]},{"type":"object","properties":{"Rectangle":{"$ref":"#/$defs/test_json_schema7__Rectangle"}},"required":["Rectangle"]}],"$defs":{"test_json_schema7__Circle":{"type":"object","properties":{"radius":{"type":"number"}},"required":["radius"]},"test_json_schema7__Rectangle":{"type":"object","properties":{"height":{"type":"number"},"width":{"type":"number"}},"required":["height","width"]}}})");
+}
+}  // namespace test_json_schema7