diff --git a/src/ArduinoJson.hpp b/src/ArduinoJson.hpp
index 0604527d..583ccddc 100644
--- a/src/ArduinoJson.hpp
+++ b/src/ArduinoJson.hpp
@@ -40,7 +40,6 @@
 #include "ArduinoJson/Object/MemberProxy.hpp"
 #include "ArduinoJson/Variant/ConverterImpl.hpp"
 #include "ArduinoJson/Variant/VariantCompare.hpp"
-#include "ArduinoJson/Variant/VariantImpl.hpp"
 
 #include "ArduinoJson/Json/JsonDeserializer.hpp"
 #include "ArduinoJson/Json/JsonSerializer.hpp"
diff --git a/src/ArduinoJson/Array/JsonArray.hpp b/src/ArduinoJson/Array/JsonArray.hpp
index 06e3cc1b..541c8e7b 100644
--- a/src/ArduinoJson/Array/JsonArray.hpp
+++ b/src/ArduinoJson/Array/JsonArray.hpp
@@ -200,3 +200,14 @@ struct Converter<JsonArray> : private detail::VariantAttorney {
 };
 
 ARDUINOJSON_END_PUBLIC_NAMESPACE
+
+ARDUINOJSON_BEGIN_PRIVATE_NAMESPACE
+
+template <typename TDerived>
+template <typename T>
+inline typename enable_if<is_same<T, JsonArray>::value, JsonArray>::type
+VariantRefBase<TDerived>::to() const {
+  return JsonArray(getPool(), variantToArray(getOrCreateData(), getPool()));
+}
+
+ARDUINOJSON_END_PRIVATE_NAMESPACE
diff --git a/src/ArduinoJson/Object/JsonObject.hpp b/src/ArduinoJson/Object/JsonObject.hpp
index 42cf5ffd..f196d8b8 100644
--- a/src/ArduinoJson/Object/JsonObject.hpp
+++ b/src/ArduinoJson/Object/JsonObject.hpp
@@ -234,3 +234,14 @@ struct Converter<JsonObject> : private detail::VariantAttorney {
 };
 
 ARDUINOJSON_END_PUBLIC_NAMESPACE
+
+ARDUINOJSON_BEGIN_PRIVATE_NAMESPACE
+
+template <typename TDerived>
+template <typename T>
+typename enable_if<is_same<T, JsonObject>::value, JsonObject>::type
+VariantRefBase<TDerived>::to() const {
+  return JsonObject(getPool(), variantToObject(getOrCreateData(), getPool()));
+}
+
+ARDUINOJSON_END_PRIVATE_NAMESPACE
diff --git a/src/ArduinoJson/Variant/JsonVariant.hpp b/src/ArduinoJson/Variant/JsonVariant.hpp
index d1f122e9..52f675e5 100644
--- a/src/ArduinoJson/Variant/JsonVariant.hpp
+++ b/src/ArduinoJson/Variant/JsonVariant.hpp
@@ -79,3 +79,37 @@ struct Converter<JsonVariantConst> : private detail::VariantAttorney {
 };
 
 ARDUINOJSON_END_PUBLIC_NAMESPACE
+
+ARDUINOJSON_BEGIN_PRIVATE_NAMESPACE
+
+template <typename TDerived>
+inline JsonVariant VariantRefBase<TDerived>::add() const {
+  return JsonVariant(getPool(),
+                     variantAddElement(getOrCreateData(), getPool()));
+}
+
+template <typename TDerived>
+inline JsonVariant VariantRefBase<TDerived>::getVariant() const {
+  return JsonVariant(getPool(), getData());
+}
+
+template <typename TDerived>
+inline JsonVariant VariantRefBase<TDerived>::getOrCreateVariant() const {
+  return JsonVariant(getPool(), getOrCreateData());
+}
+
+template <typename TDerived>
+template <typename T>
+typename enable_if<is_same<T, JsonVariant>::value, JsonVariant>::type
+VariantRefBase<TDerived>::to() const {
+  variantSetNull(getOrCreateData(), getPool());
+  return *this;
+}
+
+template <typename TDerived>
+inline void convertToJson(const VariantRefBase<TDerived>& src,
+                          JsonVariant dst) {
+  dst.set(src.template as<JsonVariantConst>());
+}
+
+ARDUINOJSON_END_PRIVATE_NAMESPACE
diff --git a/src/ArduinoJson/Variant/VariantImpl.hpp b/src/ArduinoJson/Variant/VariantImpl.hpp
deleted file mode 100644
index ead2df2d..00000000
--- a/src/ArduinoJson/Variant/VariantImpl.hpp
+++ /dev/null
@@ -1,63 +0,0 @@
-// ArduinoJson - https://arduinojson.org
-// Copyright © 2014-2023, Benoit BLANCHON
-// MIT License
-
-#pragma once
-
-#include <ArduinoJson/Array/JsonArray.hpp>
-#include <ArduinoJson/Object/JsonObject.hpp>
-#include <ArduinoJson/Variant/JsonVariant.hpp>
-
-ARDUINOJSON_BEGIN_PRIVATE_NAMESPACE
-
-template <typename TDerived>
-inline JsonVariant VariantRefBase<TDerived>::add() const {
-  return JsonVariant(getPool(),
-                     variantAddElement(getOrCreateData(), getPool()));
-}
-
-template <typename TDerived>
-inline JsonVariant VariantRefBase<TDerived>::getVariant() const {
-  return JsonVariant(getPool(), getData());
-}
-
-template <typename TDerived>
-inline JsonVariant VariantRefBase<TDerived>::getOrCreateVariant() const {
-  return JsonVariant(getPool(), getOrCreateData());
-}
-
-template <typename TDerived>
-template <typename T>
-inline typename enable_if<is_same<T, JsonArray>::value, JsonArray>::type
-VariantRefBase<TDerived>::to() const {
-  return JsonArray(getPool(), variantToArray(getOrCreateData(), getPool()));
-}
-
-template <typename TDerived>
-template <typename T>
-typename enable_if<is_same<T, JsonObject>::value, JsonObject>::type
-VariantRefBase<TDerived>::to() const {
-  return JsonObject(getPool(), variantToObject(getOrCreateData(), getPool()));
-}
-
-template <typename TDerived>
-template <typename T>
-typename enable_if<is_same<T, JsonVariant>::value, JsonVariant>::type
-VariantRefBase<TDerived>::to() const {
-  variantSetNull(getOrCreateData(), getPool());
-  return *this;
-}
-
-template <typename TDerived>
-inline void convertToJson(const VariantRefBase<TDerived>& src,
-                          JsonVariant dst) {
-  dst.set(src.template as<JsonVariantConst>());
-}
-
-inline void VariantSlot::setKey(StringNode* k) {
-  ARDUINOJSON_ASSERT(k);
-  flags_ |= OWNED_KEY_BIT;
-  key_ = k->data;
-}
-
-ARDUINOJSON_END_PRIVATE_NAMESPACE
diff --git a/src/ArduinoJson/Variant/VariantSlot.hpp b/src/ArduinoJson/Variant/VariantSlot.hpp
index 291637ad..d36fe405 100644
--- a/src/ArduinoJson/Variant/VariantSlot.hpp
+++ b/src/ArduinoJson/Variant/VariantSlot.hpp
@@ -89,7 +89,11 @@ class VariantSlot {
     key_ = k;
   }
 
-  void setKey(StringNode* k);
+  void setKey(StringNode* k) {
+    ARDUINOJSON_ASSERT(k);
+    flags_ |= OWNED_KEY_BIT;
+    key_ = k->data;
+  }
 
   const char* key() const {
     return key_;