diff --git a/lib/log.h b/lib/log.h
index cf247a8..f3b43ad 100644
--- a/lib/log.h
+++ b/lib/log.h
@@ -132,6 +132,8 @@
 extern void plog_debug (struct zlog *, const char *format, ...)
   PRINTF_ATTRIBUTE(2, 3);
 
+extern void zlog_thread_info (int log_level);
+
 /* Set logging level for the given destination.  If the log_level
    argument is ZLOG_DISABLED, then the destination is disabled.
    This function should not be used for file logging (use zlog_set_file