diff --git a/ChangeLog b/ChangeLog
index 53bd57729..a0ae498cd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -79,6 +79,7 @@
 
 1.1.5 release
 
+	* fix uTP path MTU discovery issue on windows (DF bit was not set correctly)
 	* fix python binding for torrent_handle, to be hashable
 	* fix IPv6 tracker support by performing the second announce in more cases
 	* fix utf-8 encoding check in torrent parser
diff --git a/include/libtorrent/alert_types.hpp b/include/libtorrent/alert_types.hpp
index b6ca16227..932691a36 100644
--- a/include/libtorrent/alert_types.hpp
+++ b/include/libtorrent/alert_types.hpp
@@ -897,10 +897,11 @@ namespace libtorrent {
 		piece_index_t const piece_index;
 	};
 
-	// The ``storage_moved_alert`` is generated when all the disk IO has completed and the
-	// files have been moved, as an effect of a call to ``torrent_handle::move_storage``. This
-	// is useful to synchronize with the actual disk. The ``path`` member is the new path of
-	// the storage.
+	// The ``storage_moved_alert`` is generated when all the disk IO has
+	// completed and the files have been moved, as an effect of a call to
+	// ``torrent_handle::move_storage``. This is useful to synchronize with the
+	// actual disk. The ``storage_path()`` member return the new path of the
+	// storage.
 	struct TORRENT_EXPORT storage_moved_alert final : torrent_alert
 	{
 		// internal
diff --git a/include/libtorrent/socket.hpp b/include/libtorrent/socket.hpp
index e522137aa..00ecb203d 100644
--- a/include/libtorrent/socket.hpp
+++ b/include/libtorrent/socket.hpp
@@ -160,26 +160,24 @@ namespace libtorrent {
 #endif
 
 #ifdef TORRENT_HAS_DONT_FRAGMENT
+
+	// the order of these preprocessor tests matters. Windows defines both
+	// IP_DONTFRAGMENT and IP_MTU_DISCOVER, but the latter is not supported
+	// in general, the simple option of just setting the DF bit is preferred, if
+	// it's available
+#if defined IP_DONTFRAG || defined IP_DONTFRAGMENT
+
 	struct dont_fragment
 	{
-		explicit dont_fragment(bool val)
-#ifdef IP_PMTUDISCOVER_DO
-			: m_value(val ? IP_PMTUDISC_DO : IP_PMTUDISC_DONT) {}
-#else
-			: m_value(val) {}
-#endif
+		explicit dont_fragment(bool val) : m_value(val) {}
 		template<class Protocol>
 		int level(Protocol const&) const { return IPPROTO_IP; }
 		template<class Protocol>
 		int name(Protocol const&) const
 #if defined IP_DONTFRAG
 		{ return IP_DONTFRAG; }
-#elif defined IP_MTU_DISCOVER
-		{ return IP_MTU_DISCOVER; }
-#elif defined IP_DONTFRAGMENT
+#else // defined IP_DONTFRAGMENT
 		{ return IP_DONTFRAGMENT; }
-#else
-		{}
 #endif
 		template<class Protocol>
 		int const* data(Protocol const&) const { return &m_value; }
@@ -187,6 +185,30 @@ namespace libtorrent {
 		size_t size(Protocol const&) const { return sizeof(m_value); }
 		int m_value;
 	};
+
+#else
+
+	// this is the fallback mechanism using the IP_MTU_DISCOVER option, which
+	// does a little bit more than we want, it makes the kernel track an estimate
+	// of the MTU and rejects packets immediately if they are believed to exceed
+	// it.
+	struct dont_fragment
+	{
+		explicit dont_fragment(bool val)
+			: m_value(val ? IP_PMTUDISC_DO : IP_PMTUDISC_DONT) {}
+		template<class Protocol>
+		int level(Protocol const&) const { return IPPROTO_IP; }
+		template<class Protocol>
+		int name(Protocol const&) const { return IP_MTU_DISCOVER; }
+		template<class Protocol>
+		int const* data(Protocol const&) const { return &m_value; }
+		template<class Protocol>
+		size_t size(Protocol const&) const { return sizeof(m_value); }
+		int m_value;
+	};
+
+#endif // IP_DONTFRAG vs. IP_MTU_DISCOVER
+
 #endif // TORRENT_HAS_DONT_FRAGMENT
 }