diff --git a/src/web_peer_connection.cpp b/src/web_peer_connection.cpp
index 56b5b038d..cd0c709de 100755
--- a/src/web_peer_connection.cpp
+++ b/src/web_peer_connection.cpp
@@ -413,6 +413,8 @@ namespace libtorrent
 			}
 
 			recv_buffer.begin += m_body_start;
+			// we only received the header, no data
+			if (recv_buffer.left() == 0) break;
 
 			size_type range_start;
 			size_type range_end;
@@ -548,13 +550,15 @@ namespace libtorrent
 					int copy_size = std::min(std::min(m_requests.front().length - piece_size
 						, recv_buffer.left()), int(range_end - range_start - m_received_body));
 					assert(copy_size >= 0);
-					m_piece.resize(piece_size + copy_size);
 					if (copy_size > 0)
+					{
+						m_piece.resize(piece_size + copy_size);
 						std::memcpy(&m_piece[0] + piece_size, recv_buffer.begin, copy_size);
-					recv_buffer.begin += copy_size;
-					m_received_body += copy_size;
-					m_body_start += copy_size;
-					assert(m_received_body <= range_end - range_start);
+						recv_buffer.begin += copy_size;
+						m_received_body += copy_size;
+						m_body_start += copy_size;
+					}
+					assert(m_received_body == range_end - range_start);
 				}
 			}