diff --git a/extras/tests/FailingBuilds/write_long_long.cpp b/extras/tests/FailingBuilds/write_long_long.cpp
index 2213a4dc..ec2d8179 100644
--- a/extras/tests/FailingBuilds/write_long_long.cpp
+++ b/extras/tests/FailingBuilds/write_long_long.cpp
@@ -9,10 +9,6 @@
 #  error This test requires sizeof(long) < 8
 #endif
 
-#if !ARDUINOJSON_HAS_LONG_LONG
-#  error This test requires C++11
-#endif
-
 int main() {
   DynamicJsonDocument doc(1024);
   doc["dummy"] = static_cast<long long>(42);
diff --git a/extras/tests/Numbers/convertNumber.cpp b/extras/tests/Numbers/convertNumber.cpp
index 3cf795dc..ba47d30f 100644
--- a/extras/tests/Numbers/convertNumber.cpp
+++ b/extras/tests/Numbers/convertNumber.cpp
@@ -99,7 +99,6 @@ TEST_CASE("canConvertNumber<TOut, TIn>()") {
     CHECK(canConvertNumber<uint32_t, float>(4.294967296e+9f) == false);
   }
 
-#if ARDUINOJSON_HAS_LONG_LONG
   SECTION("float -> int64_t") {
     CHECK(canConvertNumber<int64_t, float>(0) == true);
     CHECK(canConvertNumber<int64_t, float>(-9.22337204e+18f) == true);
@@ -129,5 +128,4 @@ TEST_CASE("canConvertNumber<TOut, TIn>()") {
     CHECK(canConvertNumber<uint64_t, double>(1.844674407370955166e+19) ==
           false);
   }
-#endif
 }
diff --git a/src/ArduinoJson/Configuration.hpp b/src/ArduinoJson/Configuration.hpp
index 72a8b6e4..3ebdab5c 100644
--- a/src/ArduinoJson/Configuration.hpp
+++ b/src/ArduinoJson/Configuration.hpp
@@ -5,10 +5,8 @@
 #pragma once
 
 #if __cplusplus >= 201103L
-#  define ARDUINOJSON_HAS_LONG_LONG 1
 #  define ARDUINOJSON_HAS_RVALUE_REFERENCES 1
 #else
-#  define ARDUINOJSON_HAS_LONG_LONG 0
 #  define ARDUINOJSON_HAS_RVALUE_REFERENCES 0
 #endif
 
@@ -77,8 +75,7 @@
 
 // Store integral values with long (0) or long long (1)
 #ifndef ARDUINOJSON_USE_LONG_LONG
-#  if ARDUINOJSON_HAS_LONG_LONG && defined(__SIZEOF_POINTER__) && \
-          __SIZEOF_POINTER__ >= 4 ||                              \
+#  if defined(__SIZEOF_POINTER__) && __SIZEOF_POINTER__ >= 4 || \
       defined(_MSC_VER)
 #    define ARDUINOJSON_USE_LONG_LONG 1
 #  endif
diff --git a/src/ArduinoJson/Numbers/JsonInteger.hpp b/src/ArduinoJson/Numbers/JsonInteger.hpp
index ccf852bd..494bbfde 100644
--- a/src/ArduinoJson/Numbers/JsonInteger.hpp
+++ b/src/ArduinoJson/Numbers/JsonInteger.hpp
@@ -21,12 +21,8 @@ typedef unsigned long JsonUInt;
 
 }  // namespace ARDUINOJSON_NAMESPACE
 
-#if ARDUINOJSON_HAS_LONG_LONG && !ARDUINOJSON_USE_LONG_LONG
-#  define ARDUINOJSON_ASSERT_INTEGER_TYPE_IS_SUPPORTED(T)                  \
-    static_assert(sizeof(T) <= sizeof(ARDUINOJSON_NAMESPACE::JsonInteger), \
-                  "To use 64-bit integers with ArduinoJson, you must set " \
-                  "ARDUINOJSON_USE_LONG_LONG to 1. See "                   \
-                  "https://arduinojson.org/v6/api/config/use_long_long/");
-#else
-#  define ARDUINOJSON_ASSERT_INTEGER_TYPE_IS_SUPPORTED(T)
-#endif
+#define ARDUINOJSON_ASSERT_INTEGER_TYPE_IS_SUPPORTED(T)                  \
+  static_assert(sizeof(T) <= sizeof(ARDUINOJSON_NAMESPACE::JsonInteger), \
+                "To use 64-bit integers with ArduinoJson, you must set " \
+                "ARDUINOJSON_USE_LONG_LONG to 1. See "                   \
+                "https://arduinojson.org/v6/api/config/use_long_long/");
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_integral.hpp b/src/ArduinoJson/Polyfills/type_traits/is_integral.hpp
index 97d31049..1e201b00 100644
--- a/src/ArduinoJson/Polyfills/type_traits/is_integral.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/is_integral.hpp
@@ -23,10 +23,8 @@ struct is_integral : integral_constant<bool,
     is_same<typename remove_cv<T>::type, unsigned int>::value ||
     is_same<typename remove_cv<T>::type, signed long>::value ||
     is_same<typename remove_cv<T>::type, unsigned long>::value ||
-#if ARDUINOJSON_HAS_LONG_LONG
     is_same<typename remove_cv<T>::type, signed long long>::value ||
     is_same<typename remove_cv<T>::type, unsigned long long>::value ||
-#endif
     is_same<typename remove_cv<T>::type, char>::value ||
     is_same<typename remove_cv<T>::type, bool>::value> {};
 // clang-format on
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_signed.hpp b/src/ArduinoJson/Polyfills/type_traits/is_signed.hpp
index 9c4f4341..d20a78cc 100644
--- a/src/ArduinoJson/Polyfills/type_traits/is_signed.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/is_signed.hpp
@@ -18,9 +18,7 @@ struct is_signed : integral_constant<bool,
     is_same<typename remove_cv<T>::type, signed short>::value ||
     is_same<typename remove_cv<T>::type, signed int>::value ||
     is_same<typename remove_cv<T>::type, signed long>::value ||
-#if ARDUINOJSON_HAS_LONG_LONG
     is_same<typename remove_cv<T>::type, signed long long>::value ||
-#endif
     is_same<typename remove_cv<T>::type, float>::value ||
     is_same<typename remove_cv<T>::type, double>::value> {};
 // clang-format on
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_unsigned.hpp b/src/ArduinoJson/Polyfills/type_traits/is_unsigned.hpp
index 9dfd6677..90f71fbd 100644
--- a/src/ArduinoJson/Polyfills/type_traits/is_unsigned.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/is_unsigned.hpp
@@ -17,9 +17,7 @@ struct is_unsigned : integral_constant<bool,
     is_same<typename remove_cv<T>::type, unsigned short>::value ||
     is_same<typename remove_cv<T>::type, unsigned int>::value ||
     is_same<typename remove_cv<T>::type, unsigned long>::value ||
-#if ARDUINOJSON_HAS_LONG_LONG
     is_same<typename remove_cv<T>::type, unsigned long long>::value ||
-#endif
     is_same<typename remove_cv<T>::type, bool>::value> {};
 // clang-format on
 }  // namespace ARDUINOJSON_NAMESPACE
diff --git a/src/ArduinoJson/Polyfills/type_traits/make_unsigned.hpp b/src/ArduinoJson/Polyfills/type_traits/make_unsigned.hpp
index 9b81071c..cf447997 100644
--- a/src/ArduinoJson/Polyfills/type_traits/make_unsigned.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/make_unsigned.hpp
@@ -33,10 +33,8 @@ struct make_unsigned<signed long> : type_identity<unsigned long> {};
 template <>
 struct make_unsigned<unsigned long> : type_identity<unsigned long> {};
 
-#if ARDUINOJSON_HAS_LONG_LONG
 template <>
 struct make_unsigned<signed long long> : type_identity<unsigned long long> {};
 template <>
 struct make_unsigned<unsigned long long> : type_identity<unsigned long long> {};
-#endif
 }  // namespace ARDUINOJSON_NAMESPACE