diff --git a/src/ArduinoJson/Collection/CollectionData.hpp b/src/ArduinoJson/Collection/CollectionData.hpp
index b56cf372..9a8c5bfe 100644
--- a/src/ArduinoJson/Collection/CollectionData.hpp
+++ b/src/ArduinoJson/Collection/CollectionData.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #include <stddef.h>  // size_t
 
 namespace ARDUINOJSON_NAMESPACE {
diff --git a/src/ArduinoJson/Deserialization/ArduinoStreamReader.hpp b/src/ArduinoJson/Deserialization/ArduinoStreamReader.hpp
index ab264b34..33b45e7b 100644
--- a/src/ArduinoJson/Deserialization/ArduinoStreamReader.hpp
+++ b/src/ArduinoJson/Deserialization/ArduinoStreamReader.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #if ARDUINOJSON_ENABLE_ARDUINO_STREAM
 
 #include <Stream.h>
diff --git a/src/ArduinoJson/Deserialization/CharPointerReader.hpp b/src/ArduinoJson/Deserialization/CharPointerReader.hpp
index 2de68d1a..154473bf 100644
--- a/src/ArduinoJson/Deserialization/CharPointerReader.hpp
+++ b/src/ArduinoJson/Deserialization/CharPointerReader.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 template <typename T>
diff --git a/src/ArduinoJson/Deserialization/DeserializationError.hpp b/src/ArduinoJson/Deserialization/DeserializationError.hpp
index 8707b3b0..71f8fb42 100644
--- a/src/ArduinoJson/Deserialization/DeserializationError.hpp
+++ b/src/ArduinoJson/Deserialization/DeserializationError.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #if ARDUINOJSON_ENABLE_STD_STREAM
 #include <ostream>
 #endif
diff --git a/src/ArduinoJson/Deserialization/FlashStringReader.hpp b/src/ArduinoJson/Deserialization/FlashStringReader.hpp
index 051d06ec..eca2b2a2 100644
--- a/src/ArduinoJson/Deserialization/FlashStringReader.hpp
+++ b/src/ArduinoJson/Deserialization/FlashStringReader.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #if ARDUINOJSON_ENABLE_PROGMEM
 
 namespace ARDUINOJSON_NAMESPACE {
diff --git a/src/ArduinoJson/Deserialization/IteratorReader.hpp b/src/ArduinoJson/Deserialization/IteratorReader.hpp
index f2605e48..618c1dd2 100644
--- a/src/ArduinoJson/Deserialization/IteratorReader.hpp
+++ b/src/ArduinoJson/Deserialization/IteratorReader.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 template <typename TIterator>
diff --git a/src/ArduinoJson/Deserialization/NestingLimit.hpp b/src/ArduinoJson/Deserialization/NestingLimit.hpp
index 8a2d3e87..e010590d 100644
--- a/src/ArduinoJson/Deserialization/NestingLimit.hpp
+++ b/src/ArduinoJson/Deserialization/NestingLimit.hpp
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <ArduinoJson/Configuration.hpp>
+#include <ArduinoJson/Namespace.hpp>
 
 namespace ARDUINOJSON_NAMESPACE {
 
diff --git a/src/ArduinoJson/Deserialization/StdStreamReader.hpp b/src/ArduinoJson/Deserialization/StdStreamReader.hpp
index 8996a77e..4d816528 100644
--- a/src/ArduinoJson/Deserialization/StdStreamReader.hpp
+++ b/src/ArduinoJson/Deserialization/StdStreamReader.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #if ARDUINOJSON_ENABLE_STD_STREAM
 
 #include <istream>
diff --git a/src/ArduinoJson/Json/EscapeSequence.hpp b/src/ArduinoJson/Json/EscapeSequence.hpp
index cb1792cf..5e4c475f 100644
--- a/src/ArduinoJson/Json/EscapeSequence.hpp
+++ b/src/ArduinoJson/Json/EscapeSequence.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 class EscapeSequence {
diff --git a/src/ArduinoJson/Json/Utf8.hpp b/src/ArduinoJson/Json/Utf8.hpp
index 2403309f..d79f65d8 100644
--- a/src/ArduinoJson/Json/Utf8.hpp
+++ b/src/ArduinoJson/Json/Utf8.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 namespace Utf8 {
diff --git a/src/ArduinoJson/Memory/Alignment.hpp b/src/ArduinoJson/Memory/Alignment.hpp
index 506cdce9..96acb4d3 100644
--- a/src/ArduinoJson/Memory/Alignment.hpp
+++ b/src/ArduinoJson/Memory/Alignment.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #include <stddef.h>  // size_t
 
 namespace ARDUINOJSON_NAMESPACE {
diff --git a/src/ArduinoJson/Memory/StringSlot.hpp b/src/ArduinoJson/Memory/StringSlot.hpp
index 2c599143..58d6e3bd 100644
--- a/src/ArduinoJson/Memory/StringSlot.hpp
+++ b/src/ArduinoJson/Memory/StringSlot.hpp
@@ -6,7 +6,7 @@
 
 #include <stddef.h>  // for size_t
 
-#include <ArduinoJson/Configuration.hpp>
+#include <ArduinoJson/Namespace.hpp>
 
 #define JSON_STRING_SIZE(SIZE) (SIZE)
 
diff --git a/src/ArduinoJson/MsgPack/ieee754.hpp b/src/ArduinoJson/MsgPack/ieee754.hpp
index ecb3d217..6b557d53 100644
--- a/src/ArduinoJson/MsgPack/ieee754.hpp
+++ b/src/ArduinoJson/MsgPack/ieee754.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 inline void doubleToFloat(const uint8_t d[8], uint8_t f[4]) {
diff --git a/src/ArduinoJson/Numbers/Float.hpp b/src/ArduinoJson/Numbers/Float.hpp
index 2a69a784..df8f25ff 100644
--- a/src/ArduinoJson/Numbers/Float.hpp
+++ b/src/ArduinoJson/Numbers/Float.hpp
@@ -5,6 +5,7 @@
 #pragma once
 
 #include <ArduinoJson/Configuration.hpp>
+#include <ArduinoJson/Namespace.hpp>
 
 namespace ARDUINOJSON_NAMESPACE {
 
diff --git a/src/ArduinoJson/Numbers/Integer.hpp b/src/ArduinoJson/Numbers/Integer.hpp
index fc1637c1..58fd6432 100644
--- a/src/ArduinoJson/Numbers/Integer.hpp
+++ b/src/ArduinoJson/Numbers/Integer.hpp
@@ -5,6 +5,7 @@
 #pragma once
 
 #include <ArduinoJson/Configuration.hpp>
+#include <ArduinoJson/Namespace.hpp>
 
 #include <stdint.h>  // int64_t
 
diff --git a/src/ArduinoJson/Polyfills/ctype.hpp b/src/ArduinoJson/Polyfills/ctype.hpp
index 0efb8b5e..cdb3d763 100644
--- a/src/ArduinoJson/Polyfills/ctype.hpp
+++ b/src/ArduinoJson/Polyfills/ctype.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 inline bool isdigit(char c) {
diff --git a/src/ArduinoJson/Polyfills/gsl/not_null.hpp b/src/ArduinoJson/Polyfills/gsl/not_null.hpp
index ef288e0a..4d76d13b 100644
--- a/src/ArduinoJson/Polyfills/gsl/not_null.hpp
+++ b/src/ArduinoJson/Polyfills/gsl/not_null.hpp
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
 #include <ArduinoJson/Polyfills/assert.hpp>
 
 namespace ARDUINOJSON_NAMESPACE {
diff --git a/src/ArduinoJson/Polyfills/math.hpp b/src/ArduinoJson/Polyfills/math.hpp
index c980cfe6..ace8cbaa 100644
--- a/src/ArduinoJson/Polyfills/math.hpp
+++ b/src/ArduinoJson/Polyfills/math.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 // Some libraries #define isnan() and isinf() so we need to check before
diff --git a/src/ArduinoJson/Polyfills/mpl/max.hpp b/src/ArduinoJson/Polyfills/mpl/max.hpp
index ebeaed06..16681a1f 100644
--- a/src/ArduinoJson/Polyfills/mpl/max.hpp
+++ b/src/ArduinoJson/Polyfills/mpl/max.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #include <stddef.h>  // for size_t
 
 namespace ARDUINOJSON_NAMESPACE {
diff --git a/src/ArduinoJson/Polyfills/pgmspace.hpp b/src/ArduinoJson/Polyfills/pgmspace.hpp
index 4dea1a80..4554b60d 100644
--- a/src/ArduinoJson/Polyfills/pgmspace.hpp
+++ b/src/ArduinoJson/Polyfills/pgmspace.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 // Wraps a const char* so that the our functions are picked only if the
 // originals are missing
diff --git a/src/ArduinoJson/Polyfills/safe_strcmp.hpp b/src/ArduinoJson/Polyfills/safe_strcmp.hpp
index 79f20acd..f65339d0 100644
--- a/src/ArduinoJson/Polyfills/safe_strcmp.hpp
+++ b/src/ArduinoJson/Polyfills/safe_strcmp.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 inline int8_t safe_strcmp(const char* a, const char* b) {
diff --git a/src/ArduinoJson/Polyfills/type_traits/conditional.hpp b/src/ArduinoJson/Polyfills/type_traits/conditional.hpp
index 083ab079..2b10ade7 100644
--- a/src/ArduinoJson/Polyfills/type_traits/conditional.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/conditional.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 template <bool Condition, class TrueType, class FalseType>
diff --git a/src/ArduinoJson/Polyfills/type_traits/enable_if.hpp b/src/ArduinoJson/Polyfills/type_traits/enable_if.hpp
index a707eb8c..69df161d 100644
--- a/src/ArduinoJson/Polyfills/type_traits/enable_if.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/enable_if.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 // A meta-function that return the type T if Condition is true.
diff --git a/src/ArduinoJson/Polyfills/type_traits/integral_constant.hpp b/src/ArduinoJson/Polyfills/type_traits/integral_constant.hpp
index 2a18347d..fe42c49c 100644
--- a/src/ArduinoJson/Polyfills/type_traits/integral_constant.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/integral_constant.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 template <typename T, T v>
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_array.hpp b/src/ArduinoJson/Polyfills/type_traits/is_array.hpp
index 01a5e016..0d2df37d 100644
--- a/src/ArduinoJson/Polyfills/type_traits/is_array.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/is_array.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #include <stddef.h>  // size_t
 
 namespace ARDUINOJSON_NAMESPACE {
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_base_of.hpp b/src/ArduinoJson/Polyfills/type_traits/is_base_of.hpp
index 406d39a3..d953ba21 100644
--- a/src/ArduinoJson/Polyfills/type_traits/is_base_of.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/is_base_of.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 // A meta-function that returns true if Derived inherits from TBase is an
diff --git a/src/ArduinoJson/Polyfills/type_traits/remove_const.hpp b/src/ArduinoJson/Polyfills/type_traits/remove_const.hpp
index f2c6b15b..aef6fa6b 100644
--- a/src/ArduinoJson/Polyfills/type_traits/remove_const.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/remove_const.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 // A meta-function that return the type T without the const modifier
diff --git a/src/ArduinoJson/Polyfills/type_traits/remove_reference.hpp b/src/ArduinoJson/Polyfills/type_traits/remove_reference.hpp
index edbc122a..5009b19f 100644
--- a/src/ArduinoJson/Polyfills/type_traits/remove_reference.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/remove_reference.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 // A meta-function that return the type T without the reference modifier.
diff --git a/src/ArduinoJson/Polyfills/utility.hpp b/src/ArduinoJson/Polyfills/utility.hpp
index c66a155a..f13e2c09 100644
--- a/src/ArduinoJson/Polyfills/utility.hpp
+++ b/src/ArduinoJson/Polyfills/utility.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 template <typename T>
 inline void swap(T& a, T& b) {
diff --git a/src/ArduinoJson/Serialization/DummyWriter.hpp b/src/ArduinoJson/Serialization/DummyWriter.hpp
index b54e8a53..7cf89bfa 100644
--- a/src/ArduinoJson/Serialization/DummyWriter.hpp
+++ b/src/ArduinoJson/Serialization/DummyWriter.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 class DummyWriter {
diff --git a/src/ArduinoJson/Serialization/StaticStringWriter.hpp b/src/ArduinoJson/Serialization/StaticStringWriter.hpp
index 5a27a545..b46ea90d 100644
--- a/src/ArduinoJson/Serialization/StaticStringWriter.hpp
+++ b/src/ArduinoJson/Serialization/StaticStringWriter.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 // A Print implementation that allows to write in a char[]
diff --git a/src/ArduinoJson/StringStorage/StringMover.hpp b/src/ArduinoJson/StringStorage/StringMover.hpp
index eeba11f5..a9970528 100644
--- a/src/ArduinoJson/StringStorage/StringMover.hpp
+++ b/src/ArduinoJson/StringStorage/StringMover.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 class StringMover {
diff --git a/src/ArduinoJson/Strings/SizedFlashStringAdapter.hpp b/src/ArduinoJson/Strings/SizedFlashStringAdapter.hpp
index a444c5f6..dd62c3da 100644
--- a/src/ArduinoJson/Strings/SizedFlashStringAdapter.hpp
+++ b/src/ArduinoJson/Strings/SizedFlashStringAdapter.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 class SizedFlashStringAdapter {
diff --git a/src/ArduinoJson/Strings/SizedRamStringAdapter.hpp b/src/ArduinoJson/Strings/SizedRamStringAdapter.hpp
index c8071578..af9dc739 100644
--- a/src/ArduinoJson/Strings/SizedRamStringAdapter.hpp
+++ b/src/ArduinoJson/Strings/SizedRamStringAdapter.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #include <string.h>  // strcmp
 
 namespace ARDUINOJSON_NAMESPACE {
diff --git a/src/ArduinoJson/Strings/StlStringAdapter.hpp b/src/ArduinoJson/Strings/StlStringAdapter.hpp
index fdbc8a5b..dec370fd 100644
--- a/src/ArduinoJson/Strings/StlStringAdapter.hpp
+++ b/src/ArduinoJson/Strings/StlStringAdapter.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 #include <string>
 
 namespace ARDUINOJSON_NAMESPACE {
diff --git a/src/ArduinoJson/Variant/VariantTo.hpp b/src/ArduinoJson/Variant/VariantTo.hpp
index b3da992b..bacdfe32 100644
--- a/src/ArduinoJson/Variant/VariantTo.hpp
+++ b/src/ArduinoJson/Variant/VariantTo.hpp
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <ArduinoJson/Namespace.hpp>
+
 namespace ARDUINOJSON_NAMESPACE {
 class ArrayRef;
 class ObjectRef;