diff --git a/upstream/emscripten/src/library.js b/upstream/emscripten/src/library.js
index ea4cf27..6a692bd 100644
--- a/emsdk/upstream/emscripten/src/library.js
+++ b/emsdk/upstream/emscripten/src/library.js
@@ -772,6 +772,7 @@ LibraryManager.library = {
     return ((Date.now() - _clock.start) * ({{{ cDefine('CLOCKS_PER_SEC') }}} / 1000))|0;
   },

+  time__sig: 'ii',
   time: function(ptr) {
     var ret = (Date.now()/1000)|0;
     if (ptr) {
@@ -780,6 +781,7 @@ LibraryManager.library = {
     return ret;
   },

+  difftime__sig: 'iii',
   difftime: function(time1, time0) {
     return time1 - time0;
   },