diff --git a/include/nlohmann/detail/boolean_operators.hpp b/include/nlohmann/detail/boolean_operators.hpp
deleted file mode 100644
index 06335866b..000000000
--- a/include/nlohmann/detail/boolean_operators.hpp
+++ /dev/null
@@ -1,8 +0,0 @@
-#pragma once
-
-// Header <ciso646> is removed in C++20.
-// See <https://github.com/nlohmann/json/issues/2089> for more information.
-
-#if __cplusplus <= 201703L
-    #include <ciso646> // and, not, or
-#endif
diff --git a/include/nlohmann/detail/conversions/from_json.hpp b/include/nlohmann/detail/conversions/from_json.hpp
index eca916dde..03e8d367e 100644
--- a/include/nlohmann/detail/conversions/from_json.hpp
+++ b/include/nlohmann/detail/conversions/from_json.hpp
@@ -12,7 +12,6 @@
 #include <utility> // pair, declval
 #include <valarray> // valarray
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
diff --git a/include/nlohmann/detail/conversions/to_chars.hpp b/include/nlohmann/detail/conversions/to_chars.hpp
index 9dd35fe03..c632ff2be 100644
--- a/include/nlohmann/detail/conversions/to_chars.hpp
+++ b/include/nlohmann/detail/conversions/to_chars.hpp
@@ -7,7 +7,6 @@
 #include <limits> // numeric_limits
 #include <type_traits> // conditional
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 
 namespace nlohmann
diff --git a/include/nlohmann/detail/conversions/to_json.hpp b/include/nlohmann/detail/conversions/to_json.hpp
index e412d910c..b45004fd4 100644
--- a/include/nlohmann/detail/conversions/to_json.hpp
+++ b/include/nlohmann/detail/conversions/to_json.hpp
@@ -9,7 +9,6 @@
 #include <valarray> // valarray
 #include <vector> // vector
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/iterators/iteration_proxy.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
 #include <nlohmann/detail/meta/type_traits.hpp>
diff --git a/include/nlohmann/detail/iterators/iter_impl.hpp b/include/nlohmann/detail/iterators/iter_impl.hpp
index 77dc469f6..e9a394d4c 100644
--- a/include/nlohmann/detail/iterators/iter_impl.hpp
+++ b/include/nlohmann/detail/iterators/iter_impl.hpp
@@ -3,7 +3,6 @@
 #include <iterator> // iterator, random_access_iterator_tag, bidirectional_iterator_tag, advance, next
 #include <type_traits> // conditional, is_const, remove_const
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/detail/iterators/internal_iterator.hpp>
 #include <nlohmann/detail/iterators/primitive_iterator.hpp>
diff --git a/include/nlohmann/detail/meta/cpp_future.hpp b/include/nlohmann/detail/meta/cpp_future.hpp
index 11f88acc9..dd929ee14 100644
--- a/include/nlohmann/detail/meta/cpp_future.hpp
+++ b/include/nlohmann/detail/meta/cpp_future.hpp
@@ -3,8 +3,6 @@
 #include <cstddef> // size_t
 #include <type_traits> // conditional, enable_if, false_type, integral_constant, is_constructible, is_integral, is_same, remove_cv, remove_reference, true_type
 
-#include <nlohmann/detail/boolean_operators.hpp>
-
 namespace nlohmann
 {
 namespace detail
diff --git a/include/nlohmann/detail/meta/type_traits.hpp b/include/nlohmann/detail/meta/type_traits.hpp
index 7dda32ee4..2da7b3635 100644
--- a/include/nlohmann/detail/meta/type_traits.hpp
+++ b/include/nlohmann/detail/meta/type_traits.hpp
@@ -4,7 +4,6 @@
 #include <type_traits> // false_type, is_constructible, is_integral, is_same, true_type
 #include <utility> // declval
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/iterators/iterator_traits.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
diff --git a/include/nlohmann/detail/output/serializer.hpp b/include/nlohmann/detail/output/serializer.hpp
index 1fb409436..865b8904e 100644
--- a/include/nlohmann/detail/output/serializer.hpp
+++ b/include/nlohmann/detail/output/serializer.hpp
@@ -12,7 +12,6 @@
 #include <type_traits> // is_same
 #include <utility> // move
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/conversions/to_chars.hpp>
 #include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
diff --git a/include/nlohmann/detail/value_t.hpp b/include/nlohmann/detail/value_t.hpp
index 759ca5102..0383df06f 100644
--- a/include/nlohmann/detail/value_t.hpp
+++ b/include/nlohmann/detail/value_t.hpp
@@ -5,8 +5,6 @@
 #include <cstdint> // uint8_t
 #include <string> // string
 
-#include <nlohmann/detail/boolean_operators.hpp>
-
 namespace nlohmann
 {
 namespace detail
diff --git a/include/nlohmann/json.hpp b/include/nlohmann/json.hpp
index b7b65c1c3..bbefa421d 100644
--- a/include/nlohmann/json.hpp
+++ b/include/nlohmann/json.hpp
@@ -48,7 +48,6 @@ SOFTWARE.
 
 #include <nlohmann/adl_serializer.hpp>
 #include <nlohmann/byte_container_with_subtype.hpp>
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/conversions/from_json.hpp>
 #include <nlohmann/detail/conversions/to_json.hpp>
 #include <nlohmann/detail/exceptions.hpp>
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index f55803d45..0324c11b6 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -66,16 +66,6 @@ SOFTWARE.
 #include <utility> // pair, declval
 #include <valarray> // valarray
 
-// #include <nlohmann/detail/boolean_operators.hpp>
-
-
-// Header <ciso646> is removed in C++20.
-// See <https://github.com/nlohmann/json/issues/2089> for more information.
-
-#if __cplusplus <= 201703L
-    #include <ciso646> // and, not, or
-#endif
-
 // #include <nlohmann/detail/exceptions.hpp>
 
 
@@ -2556,9 +2546,6 @@ class other_error : public exception
 #include <cstddef> // size_t
 #include <type_traits> // conditional, enable_if, false_type, integral_constant, is_constructible, is_integral, is_same, remove_cv, remove_reference, true_type
 
-// #include <nlohmann/detail/boolean_operators.hpp>
-
-
 namespace nlohmann
 {
 namespace detail
@@ -2624,8 +2611,6 @@ constexpr T static_const<T>::value;
 #include <type_traits> // false_type, is_constructible, is_integral, is_same, true_type
 #include <utility> // declval
 
-// #include <nlohmann/detail/boolean_operators.hpp>
-
 // #include <nlohmann/detail/iterators/iterator_traits.hpp>
 
 
@@ -3210,9 +3195,6 @@ struct is_constructible_tuple<T1, std::tuple<Args...>> : conjunction<std::is_con
 #include <cstdint> // uint8_t
 #include <string> // string
 
-// #include <nlohmann/detail/boolean_operators.hpp>
-
-
 namespace nlohmann
 {
 namespace detail
@@ -3681,8 +3663,6 @@ constexpr const auto& from_json = detail::static_const<detail::from_json_fn>::va
 #include <valarray> // valarray
 #include <vector> // vector
 
-// #include <nlohmann/detail/boolean_operators.hpp>
-
 // #include <nlohmann/detail/iterators/iteration_proxy.hpp>
 
 
@@ -4443,8 +4423,6 @@ class byte_container_with_subtype : public BinaryType
 
 }  // namespace nlohmann
 
-// #include <nlohmann/detail/boolean_operators.hpp>
-
 // #include <nlohmann/detail/conversions/from_json.hpp>
 
 // #include <nlohmann/detail/conversions/to_json.hpp>
@@ -10401,8 +10379,6 @@ template<typename BasicJsonType> struct internal_iterator
 #include <iterator> // iterator, random_access_iterator_tag, bidirectional_iterator_tag, advance, next
 #include <type_traits> // conditional, is_const, remove_const
 
-// #include <nlohmann/detail/boolean_operators.hpp>
-
 // #include <nlohmann/detail/exceptions.hpp>
 
 // #include <nlohmann/detail/iterators/internal_iterator.hpp>
@@ -13946,8 +13922,6 @@ class binary_writer
 #include <type_traits> // is_same
 #include <utility> // move
 
-// #include <nlohmann/detail/boolean_operators.hpp>
-
 // #include <nlohmann/detail/conversions/to_chars.hpp>
 
 
@@ -13958,8 +13932,6 @@ class binary_writer
 #include <limits> // numeric_limits
 #include <type_traits> // conditional
 
-// #include <nlohmann/detail/boolean_operators.hpp>
-
 // #include <nlohmann/detail/macro_scope.hpp>