diff --git a/include/libtorrent/debug.hpp b/include/libtorrent/debug.hpp
index 8d1ada442..12576de52 100644
--- a/include/libtorrent/debug.hpp
+++ b/include/libtorrent/debug.hpp
@@ -111,9 +111,14 @@ namespace libtorrent
 		async_t& a = _async_ops[name];
 		TORRENT_ASSERT(a.refs > 0);
 		--a.refs;
-		_wakeups.push_back(wakeup_t());
-		wakeup_t& w = _wakeups.back();
-		w.timestamp = time_now_hires();
+
+		// don't let this grow indefinitely
+		if (_wakeups.size() < 100000)
+		{
+			_wakeups.push_back(wakeup_t());
+			wakeup_t& w = _wakeups.back();
+			w.timestamp = time_now_hires();
+		}
 #ifdef __MACH__
 		task_events_info teinfo;
 		mach_msg_type_number_t t_info_count = TASK_EVENTS_INFO_COUNT;