diff --git a/src/drawing/Image.cpp b/src/drawing/Image.cpp
index e4d88b8967..0fab47c9b9 100644
--- a/src/drawing/Image.cpp
+++ b/src/drawing/Image.cpp
@@ -14,8 +14,11 @@
  *****************************************************************************/
 #pragma endregion
 
+#include <algorithm>
 #include <list>
+#include "../core/Console.hpp"
 #include "../core/Guard.hpp"
+#include "../core/Memory.hpp"
 
 extern "C"
 {
@@ -35,13 +38,34 @@ struct ImageList
 static bool                 _initialised = false;
 static std::list<ImageList> _freeLists;
 
+#ifdef DEBUG
+static std::list<ImageList> _allocatedLists;
+
+static bool AllocatedListContains(uint32 baseImageId, uint32 count)
+{
+    bool contains = std::any_of(
+        _allocatedLists.begin(),
+        _allocatedLists.end(),
+        [baseImageId, count](const ImageList &imageList) -> bool
+        {
+            return imageList.BaseId == baseImageId && imageList.Count == count;
+        });
+    return contains;
+}
+#endif
+
 static uint32 AllocateImageList(uint32 count)
 {
+    Guard::Assert(count != 0);
+
     if (!_initialised)
     {
         _initialised = true;
         _freeLists.clear();
         _freeLists.push_back({ BASE_IMAGE_ID, MAX_IMAGES });
+#ifdef DEBUG
+        _allocatedLists.clear();
+#endif
     }
 
     for (auto it = _freeLists.begin(); it != _freeLists.end(); it++)
@@ -57,6 +81,9 @@ static uint32 AllocateImageList(uint32 count)
                 _freeLists.push_back(remainder);
             }
 
+#ifdef DEBUG
+            _allocatedLists.push_back({ imageList.BaseId, count });
+#endif
             return imageList.BaseId;
         }
     }
@@ -68,6 +95,11 @@ static void FreeImageList(uint32 baseImageId, uint32 count)
     Guard::Assert(_initialised);
     Guard::Assert(baseImageId >= BASE_IMAGE_ID);
 
+#ifdef DEBUG
+    bool contains = AllocatedListContains(baseImageId, count);
+    Guard::Assert(contains);
+#endif
+
     // TODO validate that this was an allocated list
     _freeLists.push_back({ baseImageId, count });
 }
diff --git a/src/object/LargeSceneryObject.cpp b/src/object/LargeSceneryObject.cpp
index 7a76701fba..94e1679d10 100644
--- a/src/object/LargeSceneryObject.cpp
+++ b/src/object/LargeSceneryObject.cpp
@@ -81,7 +81,8 @@ void LargeSceneryObject::ReadLegacy(IReadObjectContext * context, IStream * stre
 void LargeSceneryObject::Load()
 {
     _legacyType.name = language_allocate_object_string(GetName());
-    _legacyType.image = gfx_object_allocate_images(GetImageTable()->GetImages(), GetImageTable()->GetCount());
+    _baseImageId = gfx_object_allocate_images(GetImageTable()->GetImages(), GetImageTable()->GetCount());
+    _legacyType.image = _baseImageId;
 
     _legacyType.large_scenery.tiles = _tiles;
 
@@ -112,7 +113,7 @@ void LargeSceneryObject::Load()
 void LargeSceneryObject::Unload()
 {
     language_free_object_string(_legacyType.name);
-    gfx_object_free_images(_legacyType.image, GetImageTable()->GetCount());
+    gfx_object_free_images(_baseImageId, GetImageTable()->GetCount());
 
     _legacyType.name = 0;
     _legacyType.image = 0;
diff --git a/src/object/LargeSceneryObject.h b/src/object/LargeSceneryObject.h
index 1034243988..00d67c3dbb 100644
--- a/src/object/LargeSceneryObject.h
+++ b/src/object/LargeSceneryObject.h
@@ -27,6 +27,7 @@ class LargeSceneryObject : public Object
 {
 private:
     rct_scenery_entry           _legacyType = { 0 };
+    uint32                      _baseImageId = 0;
     rct_object_entry            _sceneryTabEntry = { 0 };
     rct_large_scenery_text *    _3dFont = nullptr;
     rct_large_scenery_tile *    _tiles = nullptr;