diff --git a/src/piece_picker.cpp b/src/piece_picker.cpp
index 7f44d600c..d50af5f75 100755
--- a/src/piece_picker.cpp
+++ b/src/piece_picker.cpp
@@ -828,6 +828,8 @@ namespace libtorrent
 			, end(m_piece_map.end()); i != end; ++i)
 		{
 			int prev_prio = i->priority(m_sequenced_download_threshold);
+			assert(prev_prio < m_piece_info.size());
+			assert(pushed_out_index < m_piece_info.size());
 			assert(i->peer_count > 0);
 			--i->peer_count;
 			// if the assumption that the priority would
diff --git a/src/session_impl.cpp b/src/session_impl.cpp
index 7a893e8fe..df2065a1a 100755
--- a/src/session_impl.cpp
+++ b/src/session_impl.cpp
@@ -1140,6 +1140,7 @@ namespace detail
 
 					if (pi->optimistically_unchoked)
 					{
+						assert(!p->is_choked());
 						assert(current_optimistic_unchoke == m_connections.end());
 						current_optimistic_unchoke = i;
 					}
@@ -2129,7 +2130,10 @@ namespace detail
 			if (!i->second->is_choked()) ++unchokes;
 			if (i->second->peer_info_struct()
 				&& i->second->peer_info_struct()->optimistically_unchoked)
+			{
 				++num_optimistic;
+				assert(!i->second->is_choked());
+			}
 			if (t)
 			{
 				assert(t->get_policy().has_connection(boost::get_pointer(i->second)));