diff --git a/coding/mmap_reader.cpp b/coding/mmap_reader.cpp
index a51de38292..33c1918ce2 100644
--- a/coding/mmap_reader.cpp
+++ b/coding/mmap_reader.cpp
@@ -80,3 +80,8 @@ MmapReader * MmapReader::CreateSubReader(uint64_t pos, uint64_t size) const
   ASSERT_LESS_OR_EQUAL(pos + size, Size(), (pos, size));
   return new MmapReader(*this, m_offset + pos, size);
 }
+
+uint8_t * MmapReader::Data() const
+{
+  return m_data->m_memory;
+}
diff --git a/coding/mmap_reader.hpp b/coding/mmap_reader.hpp
index 480cd0eefa..55ff0b0ba4 100644
--- a/coding/mmap_reader.hpp
+++ b/coding/mmap_reader.hpp
@@ -22,4 +22,7 @@ public:
   virtual uint64_t Size() const;
   virtual void Read(uint64_t pos, void * p, size_t size) const;
   virtual MmapReader * CreateSubReader(uint64_t pos, uint64_t size) const;
+
+  /// Direct file/memory access
+  uint8_t * Data() const;
 };