diff --git a/lib/context.php b/lib/context.php
index 39e0bb92..9372b3c7 100644
--- a/lib/context.php
+++ b/lib/context.php
@@ -20,7 +20,7 @@ function ctx_log_msg($func, $text, $type) {
             microtime(true), # returning a float is 5.0+
             php_uname('n'),  # gethostname() is 5.3+
 			posix_getpid(),
-			posix_getpid(), //gettid(),
+			function_exists("hphp_get_thread_id") ? hphp_get_thread_id() : posix_getpid(),
             $type, $func, $text
         );
 	}