diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0d0b7b1c..ea1220c0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,8 @@
 ArduinoJson: change log
 =======================
 
+* Add `ARDUINOJSON_STRING_LENGTH_SIZE` to the namespace name
+
 v7.0.4 (2024-03-12)
 ------
 
diff --git a/extras/tests/MixedConfiguration/CMakeLists.txt b/extras/tests/MixedConfiguration/CMakeLists.txt
index 17ea0079..b8cad8e5 100644
--- a/extras/tests/MixedConfiguration/CMakeLists.txt
+++ b/extras/tests/MixedConfiguration/CMakeLists.txt
@@ -15,6 +15,9 @@ add_executable(MixedConfigurationTests
 	enable_nan_1.cpp
 	enable_progmem_1.cpp
 	issue1707.cpp
+	string_length_size_1.cpp
+	string_length_size_2.cpp
+	string_length_size_4.cpp
 	use_double_0.cpp
 	use_double_1.cpp
 	use_long_long_0.cpp
diff --git a/extras/tests/MixedConfiguration/string_length_size_1.cpp b/extras/tests/MixedConfiguration/string_length_size_1.cpp
new file mode 100644
index 00000000..8e17e3c9
--- /dev/null
+++ b/extras/tests/MixedConfiguration/string_length_size_1.cpp
@@ -0,0 +1,56 @@
+#define ARDUINOJSON_STRING_LENGTH_SIZE 1
+#include <ArduinoJson.h>
+
+#include <catch.hpp>
+#include <string>
+
+TEST_CASE("ARDUINOJSON_STRING_LENGTH_SIZE == 1") {
+  JsonDocument doc;
+
+  SECTION("set() returns true if string has 255 characters") {
+    auto result = doc.set(std::string(255, '?'));
+
+    REQUIRE(result == true);
+    REQUIRE(doc.overflowed() == false);
+  }
+
+  SECTION("set() returns false if string has 256 characters") {
+    auto result = doc.set(std::string(256, '?'));
+
+    REQUIRE(result == false);
+    REQUIRE(doc.overflowed() == true);
+  }
+
+  SECTION("deserializeJson() returns Ok if string has 255 characters") {
+    auto input = "\"" + std::string(255, '?') + "\"";
+
+    auto err = deserializeJson(doc, input);
+
+    REQUIRE(err == DeserializationError::Ok);
+  }
+
+  SECTION("deserializeJson() returns NoMemory if string has 256 characters") {
+    auto input = "\"" + std::string(256, '?') + "\"";
+
+    auto err = deserializeJson(doc, input);
+
+    REQUIRE(err == DeserializationError::NoMemory);
+  }
+
+  SECTION("deserializeMsgPack() returns Ok of string has 255 characters") {
+    auto input = "\xd9\xff" + std::string(255, '?');
+
+    auto err = deserializeMsgPack(doc, input);
+
+    REQUIRE(err == DeserializationError::Ok);
+  }
+
+  SECTION(
+      "deserializeMsgPack() returns NoMemory of string has 256 characters") {
+    auto input = std::string("\xda\x01\x00", 3) + std::string(256, '?');
+
+    auto err = deserializeMsgPack(doc, input);
+
+    REQUIRE(err == DeserializationError::NoMemory);
+  }
+}
diff --git a/extras/tests/MixedConfiguration/string_length_size_2.cpp b/extras/tests/MixedConfiguration/string_length_size_2.cpp
new file mode 100644
index 00000000..669905ef
--- /dev/null
+++ b/extras/tests/MixedConfiguration/string_length_size_2.cpp
@@ -0,0 +1,57 @@
+#define ARDUINOJSON_STRING_LENGTH_SIZE 2
+#include <ArduinoJson.h>
+
+#include <catch.hpp>
+#include <string>
+
+TEST_CASE("ARDUINOJSON_STRING_LENGTH_SIZE == 2") {
+  JsonDocument doc;
+
+  SECTION("set() returns true if string has 65535 characters") {
+    auto result = doc.set(std::string(65535, '?'));
+
+    REQUIRE(result == true);
+    REQUIRE(doc.overflowed() == false);
+  }
+
+  SECTION("set() returns false if string has 65536 characters") {
+    auto result = doc.set(std::string(65536, '?'));
+
+    REQUIRE(result == false);
+    REQUIRE(doc.overflowed() == true);
+  }
+
+  SECTION("deserializeJson() returns Ok if string has 65535 characters") {
+    auto input = "\"" + std::string(65535, '?') + "\"";
+
+    auto err = deserializeJson(doc, input);
+
+    REQUIRE(err == DeserializationError::Ok);
+  }
+
+  SECTION("deserializeJson() returns NoMemory if string has 65536 characters") {
+    auto input = "\"" + std::string(65536, '?') + "\"";
+
+    auto err = deserializeJson(doc, input);
+
+    REQUIRE(err == DeserializationError::NoMemory);
+  }
+
+  SECTION("deserializeMsgPack() returns Ok of string has 65535 characters") {
+    auto input = "\xda\xff\xff" + std::string(65535, '?');
+
+    auto err = deserializeMsgPack(doc, input);
+
+    REQUIRE(err == DeserializationError::Ok);
+  }
+
+  SECTION(
+      "deserializeMsgPack() returns NoMemory of string has 65536 characters") {
+    auto input =
+        std::string("\xdb\x00\x01\x00\x00", 5) + std::string(65536, '?');
+
+    auto err = deserializeMsgPack(doc, input);
+
+    REQUIRE(err == DeserializationError::NoMemory);
+  }
+}
diff --git a/extras/tests/MixedConfiguration/string_length_size_4.cpp b/extras/tests/MixedConfiguration/string_length_size_4.cpp
new file mode 100644
index 00000000..e448743c
--- /dev/null
+++ b/extras/tests/MixedConfiguration/string_length_size_4.cpp
@@ -0,0 +1,32 @@
+#define ARDUINOJSON_STRING_LENGTH_SIZE 4
+#include <ArduinoJson.h>
+
+#include <catch.hpp>
+#include <string>
+
+TEST_CASE("ARDUINOJSON_STRING_LENGTH_SIZE == 4") {
+  JsonDocument doc;
+
+  SECTION("set() returns true if string has 65536 characters") {
+    auto result = doc.set(std::string(65536, '?'));
+
+    REQUIRE(result == true);
+    REQUIRE(doc.overflowed() == false);
+  }
+
+  SECTION("deserializeJson() returns Ok if string has 65536 characters") {
+    auto input = "\"" + std::string(65536, '?') + "\"";
+
+    auto err = deserializeJson(doc, input);
+
+    REQUIRE(err == DeserializationError::Ok);
+  }
+
+  SECTION("deserializeMsgPack() returns Ok of string has 65536 characters") {
+    auto input = "\xda\xff\xff" + std::string(65536, '?');
+
+    auto err = deserializeMsgPack(doc, input);
+
+    REQUIRE(err == DeserializationError::Ok);
+  }
+}
diff --git a/src/ArduinoJson/Namespace.hpp b/src/ArduinoJson/Namespace.hpp
index 40e005f7..da7a4494 100644
--- a/src/ArduinoJson/Namespace.hpp
+++ b/src/ArduinoJson/Namespace.hpp
@@ -10,16 +10,16 @@
 
 #ifndef ARDUINOJSON_VERSION_NAMESPACE
 
-#  define ARDUINOJSON_VERSION_NAMESPACE                                    \
-    ARDUINOJSON_CONCAT4(ARDUINOJSON_VERSION_MACRO,                         \
-                        ARDUINOJSON_BIN2ALPHA(ARDUINOJSON_ENABLE_PROGMEM,  \
-                                              ARDUINOJSON_USE_LONG_LONG,   \
-                                              ARDUINOJSON_USE_DOUBLE, 1),  \
-                        ARDUINOJSON_BIN2ALPHA(ARDUINOJSON_ENABLE_NAN,      \
-                                              ARDUINOJSON_ENABLE_INFINITY, \
-                                              ARDUINOJSON_ENABLE_COMMENTS, \
-                                              ARDUINOJSON_DECODE_UNICODE), \
-                        ARDUINOJSON_SLOT_ID_SIZE)
+#  define ARDUINOJSON_VERSION_NAMESPACE                               \
+    ARDUINOJSON_CONCAT5(                                              \
+        ARDUINOJSON_VERSION_MACRO,                                    \
+        ARDUINOJSON_BIN2ALPHA(ARDUINOJSON_ENABLE_PROGMEM,             \
+                              ARDUINOJSON_USE_LONG_LONG,              \
+                              ARDUINOJSON_USE_DOUBLE, 1),             \
+        ARDUINOJSON_BIN2ALPHA(                                        \
+            ARDUINOJSON_ENABLE_NAN, ARDUINOJSON_ENABLE_INFINITY,      \
+            ARDUINOJSON_ENABLE_COMMENTS, ARDUINOJSON_DECODE_UNICODE), \
+        ARDUINOJSON_SLOT_ID_SIZE, ARDUINOJSON_STRING_LENGTH_SIZE)
 
 #endif
 
diff --git a/src/ArduinoJson/Polyfills/preprocessor.hpp b/src/ArduinoJson/Polyfills/preprocessor.hpp
index df76497f..ca565f72 100644
--- a/src/ArduinoJson/Polyfills/preprocessor.hpp
+++ b/src/ArduinoJson/Polyfills/preprocessor.hpp
@@ -6,8 +6,12 @@
 
 #define ARDUINOJSON_CONCAT_(A, B) A##B
 #define ARDUINOJSON_CONCAT2(A, B) ARDUINOJSON_CONCAT_(A, B)
+#define ARDUINOJSON_CONCAT3(A, B, C) \
+  ARDUINOJSON_CONCAT2(ARDUINOJSON_CONCAT2(A, B), C)
 #define ARDUINOJSON_CONCAT4(A, B, C, D) \
-  ARDUINOJSON_CONCAT2(ARDUINOJSON_CONCAT2(A, B), ARDUINOJSON_CONCAT2(C, D))
+  ARDUINOJSON_CONCAT2(ARDUINOJSON_CONCAT3(A, B, C), D)
+#define ARDUINOJSON_CONCAT5(A, B, C, D, E) \
+  ARDUINOJSON_CONCAT2(ARDUINOJSON_CONCAT4(A, B, C, D), E)
 
 #define ARDUINOJSON_BIN2ALPHA_0000() A
 #define ARDUINOJSON_BIN2ALPHA_0001() B