diff --git a/src/common/buffer.cc b/src/common/buffer.cc
index 38eb82c8c..937e89efc 100644
--- a/src/common/buffer.cc
+++ b/src/common/buffer.cc
@@ -1017,11 +1017,28 @@ Buffer::Iterator::Write (Iterator start, Iterator end)
   NS_ASSERT (m_data != start.m_data);
   uint32_t size = end.m_current - start.m_current;
   Iterator cur = start;
-  for (uint32_t i = 0; i < size; i++)
+  NS_ASSERT (CheckNoZero (m_current, m_current + size));
+  if (start.m_current <= start.m_zeroStart)
     {
-      uint8_t data = cur.ReadU8 ();
-      WriteU8 (data);
+      uint32_t toCopy = std::min (size, start.m_zeroStart - start.m_current);
+      memcpy (&m_data[m_current], &start.m_data[start.m_current], toCopy);
+      start.m_current += toCopy;
+      m_current += toCopy;
+      size -= toCopy;
     }
+  if (start.m_current <= start.m_zeroEnd)
+    {
+      uint32_t toCopy = std::min (size, start.m_zeroEnd - start.m_current);
+      memset (&m_data[m_current], 0, toCopy);
+      start.m_current += toCopy;
+      m_current += toCopy;
+      size -= toCopy;
+    }
+  uint32_t toCopy = std::min (size, start.m_dataEnd - start.m_current);
+  uint8_t *from = &start.m_data[start.m_current - (start.m_zeroEnd-start.m_zeroStart)];
+  uint8_t *to = &m_data[m_current];
+  memcpy (to, from, toCopy);
+  m_current += toCopy;
 }
 
 void 
@@ -1117,10 +1134,18 @@ Buffer::Iterator::WriteHtonU64 (uint64_t data)
 void 
 Buffer::Iterator::Write (uint8_t const*buffer, uint32_t size)
 {
-  for (uint32_t i = 0; i < size; i++)
+  NS_ASSERT (CheckNoZero (m_current, size));
+  uint8_t *to;
+  if (m_current <= m_zeroStart)
     {
-      WriteU8 (buffer[i]);
+      to = &m_data[m_current];
     }
+  else
+    {
+      to = &m_data[m_current - (m_zeroEnd - m_zeroStart)];
+    }
+  memcpy (to, buffer, size);
+  m_current += size;
 }
 
 uint16_t 
@@ -1611,6 +1636,23 @@ BufferTest::DoRun (void)
   ENSURE_WRITTEN_BYTES (buffer, 7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x66);
   ENSURE_WRITTEN_BYTES (frag0, 7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x66);
 
+  buffer = Buffer (5);
+  buffer.AddAtStart (2);
+  i = buffer.Begin ();
+  i.WriteU8 (0x1);
+  i.WriteU8 (0x2);
+  buffer.AddAtEnd (2);
+  i = buffer.End ();
+  i.Prev (2);
+  i.WriteU8 (0x3);
+  i.WriteU8 (0x4);
+  ENSURE_WRITTEN_BYTES (buffer, 9, 0x1, 0x2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3, 0x4);
+  Buffer other;
+  other.AddAtStart (9);
+  i = other.Begin ();
+  i.Write (buffer.Begin (), buffer.End ());
+  ENSURE_WRITTEN_BYTES (other, 9, 0x1, 0x2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3, 0x4);
+
   return GetErrorStatus ();
 }
 //-----------------------------------------------------------------------------