diff --git a/src/openrct2/Cheats.cpp b/src/openrct2/Cheats.cpp
index e458285e6b..7b9f239043 100644
--- a/src/openrct2/Cheats.cpp
+++ b/src/openrct2/Cheats.cpp
@@ -95,7 +95,7 @@ void CheatsSerialise(DataSerialiser& ds)
 
     if (ds.IsSaving())
     {
-        MemoryStream& stream = ds.GetStream();
+        IStream& stream = ds.GetStream();
 
         // Temporarily write 0, will be updated after every cheat is written.
         uint64_t countOffset = stream.GetPosition();
diff --git a/src/openrct2/actions/GameAction.cpp b/src/openrct2/actions/GameAction.cpp
index b6789b86e5..8a2d5bc99c 100644
--- a/src/openrct2/actions/GameAction.cpp
+++ b/src/openrct2/actions/GameAction.cpp
@@ -106,7 +106,7 @@ namespace GameActions
         action->Serialise(dsOut);
 
         // Serialise into new action.
-        MemoryStream& stream = dsOut.GetStream();
+        IStream& stream = dsOut.GetStream();
         stream.SetPosition(0);
 
         DataSerialiser dsIn(false, stream);
diff --git a/src/openrct2/core/DataSerialiser.h b/src/openrct2/core/DataSerialiser.h
index 367567d6f9..7549b2df34 100644
--- a/src/openrct2/core/DataSerialiser.h
+++ b/src/openrct2/core/DataSerialiser.h
@@ -17,23 +17,23 @@ class DataSerialiser
 {
 private:
     MemoryStream _stream;
-    IStream* _activeStream = nullptr;
+    IStream& _activeStream;
     bool _isSaving = false;
     bool _isLogging = false;
 
 public:
     DataSerialiser(bool isSaving)
-        : _isSaving(isSaving)
+        : _activeStream(_stream)
+        , _isSaving(isSaving)
         , _isLogging(false)
     {
-        _activeStream = &_stream;
     }
 
     DataSerialiser(bool isSaving, IStream& stream, bool isLogging = false)
-        : _isSaving(isSaving)
+        : _activeStream(stream)
+        , _isSaving(isSaving)
         , _isLogging(isLogging)
     {
-        _activeStream = &stream;
     }
 
     bool IsSaving() const
@@ -46,9 +46,9 @@ public:
         return !_isSaving;
     }
 
-    MemoryStream& GetStream()
+    IStream& GetStream()
     {
-        return _stream;
+        return _activeStream;
     }
 
     template<typename T> DataSerialiser& operator<<(const T& data)
@@ -56,13 +56,13 @@ public:
         if (!_isLogging)
         {
             if (_isSaving)
-                DataSerializerTraits<T>::encode(_activeStream, data);
+                DataSerializerTraits<T>::encode(&_activeStream, data);
             else
-                DataSerializerTraits<T>::decode(_activeStream, const_cast<T&>(data));
+                DataSerializerTraits<T>::decode(&_activeStream, const_cast<T&>(data));
         }
         else
         {
-            DataSerializerTraits<T>::log(_activeStream, data);
+            DataSerializerTraits<T>::log(&_activeStream, data);
         }
 
         return *this;
@@ -73,13 +73,13 @@ public:
         if (!_isLogging)
         {
             if (_isSaving)
-                DataSerializerTraits<DataSerialiserTag<T>>::encode(_activeStream, data);
+                DataSerializerTraits<DataSerialiserTag<T>>::encode(&_activeStream, data);
             else
-                DataSerializerTraits<DataSerialiserTag<T>>::decode(_activeStream, data);
+                DataSerializerTraits<DataSerialiserTag<T>>::decode(&_activeStream, data);
         }
         else
         {
-            DataSerializerTraits<DataSerialiserTag<T>>::log(_activeStream, data);
+            DataSerializerTraits<DataSerialiserTag<T>>::log(&_activeStream, data);
         }
 
         return *this;
diff --git a/src/openrct2/core/FileStream.hpp b/src/openrct2/core/FileStream.hpp
index 0839b9994f..0fb34679e7 100644
--- a/src/openrct2/core/FileStream.hpp
+++ b/src/openrct2/core/FileStream.hpp
@@ -216,4 +216,9 @@ public:
         size_t readBytes = fread(buffer, 1, (size_t)length, _file);
         return readBytes;
     }
+
+    const void* GetData() const override
+    {
+        return nullptr;
+    }
 };
diff --git a/src/openrct2/core/IStream.hpp b/src/openrct2/core/IStream.hpp
index c578aaf7b9..0ded91b216 100644
--- a/src/openrct2/core/IStream.hpp
+++ b/src/openrct2/core/IStream.hpp
@@ -49,6 +49,8 @@ interface IStream
 
     virtual uint64_t TryRead(void* buffer, uint64_t length) abstract;
 
+    virtual const void* GetData() const abstract;
+
     ///////////////////////////////////////////////////////////////////////////
     // Helper methods
     ///////////////////////////////////////////////////////////////////////////
diff --git a/src/openrct2/core/MemoryStream.h b/src/openrct2/core/MemoryStream.h
index e1ac6870fb..1401d1a87b 100644
--- a/src/openrct2/core/MemoryStream.h
+++ b/src/openrct2/core/MemoryStream.h
@@ -42,7 +42,7 @@ public:
 
     MemoryStream& operator=(MemoryStream&& mv);
 
-    const void* GetData() const;
+    const void* GetData() const override;
     void* GetDataCopy() const;
     void* TakeData();