diff --git a/extras/conf_test/avr.cpp b/extras/conf_test/avr.cpp
index 35105ef40..eeac6c0dd 100644
--- a/extras/conf_test/avr.cpp
+++ b/extras/conf_test/avr.cpp
@@ -10,8 +10,7 @@ static_assert(ARDUINOJSON_LITTLE_ENDIAN == 1, "ARDUINOJSON_LITTLE_ENDIAN");
 
 static_assert(ARDUINOJSON_USE_DOUBLE == 0, "ARDUINOJSON_USE_DOUBLE");
 
-static_assert(sizeof(ArduinoJson::detail::VariantData) == 6,
-              "sizeof(VariantData)");
+static_assert(ArduinoJson::detail::ResourceManager::slotSize == 6, "slot size");
 
 void setup() {}
 void loop() {}
diff --git a/extras/conf_test/esp8266.cpp b/extras/conf_test/esp8266.cpp
index 0b3d9f63a..18d0d7536 100644
--- a/extras/conf_test/esp8266.cpp
+++ b/extras/conf_test/esp8266.cpp
@@ -8,8 +8,7 @@ static_assert(ARDUINOJSON_LITTLE_ENDIAN == 1, "ARDUINOJSON_LITTLE_ENDIAN");
 
 static_assert(ARDUINOJSON_USE_DOUBLE == 1, "ARDUINOJSON_USE_DOUBLE");
 
-static_assert(sizeof(ArduinoJson::detail::VariantData) == 8,
-              "sizeof(VariantData)");
+static_assert(ArduinoJson::detail::ResourceManager::slotSize == 8, "slot size");
 
 void setup() {}
 void loop() {}
diff --git a/extras/conf_test/x64.cpp b/extras/conf_test/x64.cpp
index 0b6fd16bc..c7ce9ae24 100644
--- a/extras/conf_test/x64.cpp
+++ b/extras/conf_test/x64.cpp
@@ -8,7 +8,7 @@ static_assert(ARDUINOJSON_LITTLE_ENDIAN == 1, "ARDUINOJSON_LITTLE_ENDIAN");
 
 static_assert(ARDUINOJSON_USE_DOUBLE == 1, "ARDUINOJSON_USE_DOUBLE");
 
-static_assert(sizeof(ArduinoJson::detail::VariantData) == 16,
-              "sizeof(VariantData)");
+static_assert(ArduinoJson::detail::ResourceManager::slotSize == 16,
+              "slot size");
 
 int main() {}
diff --git a/extras/conf_test/x86.cpp b/extras/conf_test/x86.cpp
index befe73d35..a5f335e85 100644
--- a/extras/conf_test/x86.cpp
+++ b/extras/conf_test/x86.cpp
@@ -8,7 +8,6 @@ static_assert(ARDUINOJSON_LITTLE_ENDIAN == 1, "ARDUINOJSON_LITTLE_ENDIAN");
 
 static_assert(ARDUINOJSON_USE_DOUBLE == 1, "ARDUINOJSON_USE_DOUBLE");
 
-static_assert(sizeof(ArduinoJson::detail::VariantData) == 8,
-              "sizeof(VariantData)");
+static_assert(ArduinoJson::detail::ResourceManager::slotSize == 8, "slot size");
 
 int main() {}
diff --git a/extras/tests/ResourceManager/shrinkToFit.cpp b/extras/tests/ResourceManager/shrinkToFit.cpp
index a09fd8a3b..d35ee3430 100644
--- a/extras/tests/ResourceManager/shrinkToFit.cpp
+++ b/extras/tests/ResourceManager/shrinkToFit.cpp
@@ -28,7 +28,7 @@ TEST_CASE("ResourceManager::shrinkToFit()") {
     REQUIRE(spyingAllocator.log() ==
             AllocatorLog{
                 Allocate(sizeofPool()),
-                Reallocate(sizeofPool(), sizeof(VariantData)),
+                Reallocate(sizeofPool(), sizeofPool(1)),
             });
   }
 
@@ -49,7 +49,7 @@ TEST_CASE("ResourceManager::shrinkToFit()") {
 
     REQUIRE(spyingAllocator.log() ==
             AllocatorLog{
-                Reallocate(sizeofPool(), sizeof(VariantData)),
+                Reallocate(sizeofPool(), sizeofPool(1)),
                 Reallocate(sizeofPoolList(ARDUINOJSON_INITIAL_POOL_COUNT * 2),
                            sizeofPoolList(ARDUINOJSON_INITIAL_POOL_COUNT + 1)),
             });
diff --git a/src/ArduinoJson/Array/ArrayImpl.hpp b/src/ArduinoJson/Array/ArrayImpl.hpp
index d09aaa3f2..9599a5eb9 100644
--- a/src/ArduinoJson/Array/ArrayImpl.hpp
+++ b/src/ArduinoJson/Array/ArrayImpl.hpp
@@ -73,7 +73,7 @@ inline bool ArrayData::addValue(T&& value, ResourceManager* resources) {
 
 // Returns the size (in bytes) of an array with n elements.
 constexpr size_t sizeofArray(size_t n) {
-  return n * sizeof(VariantData);
+  return n * ResourceManager::slotSize;
 }
 
 ARDUINOJSON_END_PRIVATE_NAMESPACE
diff --git a/src/ArduinoJson/Memory/ResourceManager.hpp b/src/ArduinoJson/Memory/ResourceManager.hpp
index 53d425cf9..c8e0d5be0 100644
--- a/src/ArduinoJson/Memory/ResourceManager.hpp
+++ b/src/ArduinoJson/Memory/ResourceManager.hpp
@@ -26,6 +26,8 @@ class ResourceManager {
   };
 
  public:
+  constexpr static size_t slotSize = sizeof(SlotData);
+
   ResourceManager(Allocator* allocator = DefaultAllocator::instance())
       : allocator_(allocator), overflowed_(false) {}
 
diff --git a/src/ArduinoJson/Object/ObjectImpl.hpp b/src/ArduinoJson/Object/ObjectImpl.hpp
index a5354d1dd..024d77237 100644
--- a/src/ArduinoJson/Object/ObjectImpl.hpp
+++ b/src/ArduinoJson/Object/ObjectImpl.hpp
@@ -70,7 +70,7 @@ inline VariantData* ObjectData::addMember(TAdaptedString key,
 
 // Returns the size (in bytes) of an object with n members.
 constexpr size_t sizeofObject(size_t n) {
-  return 2 * n * sizeof(VariantData);
+  return 2 * n * ResourceManager::slotSize;
 }
 
 ARDUINOJSON_END_PRIVATE_NAMESPACE