diff --git a/lib/bytes.cc b/lib/bytes.cc
index 3a926e67..fa651430 100644
--- a/lib/bytes.cc
+++ b/lib/bytes.cc
@@ -273,6 +273,16 @@ ByteWriter Bytes::writer()
     return ByteWriter(*this);
 }
 
+ByteWriter& ByteWriter::operator +=(std::istream& stream)
+{
+    Bytes buffer(4096);
+
+    while (stream.read((char*) buffer.begin(), buffer.size()))
+        this->append(buffer);
+    this->append(buffer.slice(0, stream.gcount()));
+    return *this;
+}
+
 void BitWriter::push(uint32_t bits, size_t size)
 {
     bits <<= 32-size;
diff --git a/lib/bytes.h b/lib/bytes.h
index 6408bd0c..0dc5ebb9 100644
--- a/lib/bytes.h
+++ b/lib/bytes.h
@@ -69,7 +69,7 @@ public:
 
     unsigned pos = 0;
     bool eof() const
-    { return pos == _bytes.size(); }
+    { return pos >= _bytes.size(); }
 
     ByteReader& seek(unsigned pos)
     {
@@ -77,6 +77,12 @@ public:
         return *this;
     }
 
+    ByteReader& skip(int delta)
+    {
+        this->pos += delta;
+        return *this;
+    }
+
     const Bytes read(unsigned len)
     {
         const Bytes bytes = _bytes.slice(pos, len);
@@ -256,11 +262,18 @@ public:
         return *this;
     }
 
+    ByteWriter& operator += (std::istream& stream);
+
     ByteWriter& append(const Bytes data)
     {
         return *this += data;
     }
 
+    ByteWriter& append(std::istream& stream)
+    {
+        return *this += stream;
+    }
+
 private:
     Bytes& _bytes;
 };