diff --git a/src/peer_connection.cpp b/src/peer_connection.cpp
index 2c28692fc..4b456c7b1 100644
--- a/src/peer_connection.cpp
+++ b/src/peer_connection.cpp
@@ -3063,7 +3063,9 @@ namespace libtorrent
 
 	void peer_connection::fill_send_buffer()
 	{
+#ifdef TORRENT_EXPENSIVE_INVARIANT_CHECKS
 		INVARIANT_CHECK;
+#endif
 
 		boost::shared_ptr<torrent> t = m_torrent.lock();
 		if (!t) return;
@@ -4022,7 +4024,9 @@ namespace libtorrent
 
 	void peer_connection::keep_alive()
 	{
+#ifdef TORRENT_EXPENSIVE_INVARIANT_CHECKS
 		INVARIANT_CHECK;
+#endif
 
 		time_duration d;
 		d = time_now() - m_last_sent;
diff --git a/src/piece_picker.cpp b/src/piece_picker.cpp
index 8935609fa..c1941a6ff 100644
--- a/src/piece_picker.cpp
+++ b/src/piece_picker.cpp
@@ -2177,7 +2177,9 @@ namespace libtorrent
 	// a peer disconnects. The piece might be in any state
 	void piece_picker::abort_download(piece_block block)
 	{
+#ifdef TORRENT_EXPENSIVE_INVARIANT_CHECKS
 		TORRENT_PIECE_PICKER_INVARIANT_CHECK;
+#endif
 
 		TORRENT_ASSERT(block.piece_index >= 0);
 		TORRENT_ASSERT(block.block_index >= 0);