Index: include/AdblockPlus/DefaultFileSystem.h
===================================================================
--- a/include/AdblockPlus/DefaultFileSystem.h
+++ b/include/AdblockPlus/DefaultFileSystem.h
@@ -32,18 +32,18 @@
    * `FileSystem` implementation that interacts directly with the operating
    * system's file system.
    * All paths are considered relative to the base path, or to the current
    * working directory if no base path is set (see `SetBasePath()`).
    */
   class DefaultFileSystem : public FileSystem
   {
   public:
-    std::shared_ptr<std::istream> Read(const std::string& path) const;
-    void Write(const std::string& path, std::istream& data);
+    IOBuffer Read(const std::string& path) const;
+    void Write(const std::string& path, const IOBuffer& data);
     void Move(const std::string& fromPath, const std::string& toPath);
     void Remove(const std::string& path);
     StatResult Stat(const std::string& path) const;
     std::string Resolve(const std::string& path) const;
 
     /**
      * Sets the base path, all paths are considered relative to it.
      * @param path Base path.