diff --git a/CHANGELOG.md b/CHANGELOG.md
index cd09639e..e039c842 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@ HEAD
 * Fix compatibility with the Blynk libary (issue #1914)
 * Fix double lookup in `to<JsonVariant>()`
 * Fix double call to `size()` in `serializeMsgPack()`
+* Include `ARDUINOJSON_SLOT_OFFSET_SIZE` in the namespace name
 
 v6.21.2 (2023-04-12)
 -------
diff --git a/src/ArduinoJson/Namespace.hpp b/src/ArduinoJson/Namespace.hpp
index 84447de5..7cce1748 100644
--- a/src/ArduinoJson/Namespace.hpp
+++ b/src/ArduinoJson/Namespace.hpp
@@ -11,14 +11,15 @@
 #ifndef ARDUINOJSON_VERSION_NAMESPACE
 
 #  define ARDUINOJSON_VERSION_NAMESPACE                                       \
-    ARDUINOJSON_CONCAT3(                                                      \
+    ARDUINOJSON_CONCAT4(                                                      \
         ARDUINOJSON_VERSION_MACRO,                                            \
         ARDUINOJSON_BIN2ALPHA(                                                \
             ARDUINOJSON_ENABLE_PROGMEM, ARDUINOJSON_USE_LONG_LONG,            \
             ARDUINOJSON_USE_DOUBLE, ARDUINOJSON_ENABLE_STRING_DEDUPLICATION), \
         ARDUINOJSON_BIN2ALPHA(                                                \
             ARDUINOJSON_ENABLE_NAN, ARDUINOJSON_ENABLE_INFINITY,              \
-            ARDUINOJSON_ENABLE_COMMENTS, ARDUINOJSON_DECODE_UNICODE))
+            ARDUINOJSON_ENABLE_COMMENTS, ARDUINOJSON_DECODE_UNICODE),         \
+        ARDUINOJSON_SLOT_OFFSET_SIZE)
 
 #endif
 
diff --git a/src/ArduinoJson/Polyfills/preprocessor.hpp b/src/ArduinoJson/Polyfills/preprocessor.hpp
index 78174143..6998f697 100644
--- a/src/ArduinoJson/Polyfills/preprocessor.hpp
+++ b/src/ArduinoJson/Polyfills/preprocessor.hpp
@@ -6,8 +6,8 @@
 
 #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))
 
 #define ARDUINOJSON_BIN2ALPHA_0000() A
 #define ARDUINOJSON_BIN2ALPHA_0001() B