diff --git a/src/part_file.cpp b/src/part_file.cpp
index bba8bb1cb..b842a2b8f 100644
--- a/src/part_file.cpp
+++ b/src/part_file.cpp
@@ -98,7 +98,7 @@ namespace libtorrent
 		if (!ec)
 		{
 			// parse header
-			boost::scoped_array<boost::uint32_t> header(new boost::uint32_t[m_header_size]);
+			boost::scoped_array<boost::uint32_t> header(new boost::uint32_t[m_header_size / 4]);
 			file::iovec_t b = {header.get(), size_t(m_header_size) };
 			int n = m_file.readv(0, &b, 1, ec);
 			if (ec) return;
@@ -396,7 +396,7 @@ namespace libtorrent
 		open_file(file::read_write, ec);
 		if (ec) return;
 
-		boost::scoped_array<boost::uint32_t> header(new boost::uint32_t[m_header_size]);
+		boost::scoped_array<boost::uint32_t> header(new boost::uint32_t[m_header_size / 4]);
 
 		using namespace libtorrent::detail;