diff --git a/src/disk_io_thread.cpp b/src/disk_io_thread.cpp
index f091c3db8..012658e59 100644
--- a/src/disk_io_thread.cpp
+++ b/src/disk_io_thread.cpp
@@ -1153,7 +1153,8 @@ namespace libtorrent
 #ifndef BOOST_NO_EXCEPTIONS
 			try {
 #endif
-				TORRENT_ASSERT(ret != -2 || !j.str.empty());
+				TORRENT_ASSERT(ret != -2 || !j.str.empty()
+					|| j.action == disk_io_job::hash);
 				if (handler) m_ios.post(bind(handler, ret, j));
 #ifndef BOOST_NO_EXCEPTIONS
 			} catch (std::exception&)