diff --git a/emsdk/emscripten/tag-1.38.22/src/library.js b/emsdk/emscripten/tag-1.38.22/src/library.js
index 82537bb3e..8e2e43128 100644
--- a/emsdk/emscripten/tag-1.38.22/src/library.js
+++ b/emsdk/emscripten/tag-1.38.22/src/library.js
@@ -1781,6 +1781,12 @@ LibraryManager.library = {
         }
       }
 
+      for (var sym in lib_module) {
+        if (sym.startsWith('dynCall_') && !Module.hasOwnProperty(sym)) {
+          Module[sym] = lib_module[sym];
+        }
+      }
+
       // Not all browsers support Object.keys().
       var handle = 1;
       for (var key in DLFCN.loadedLibs) {
diff --git a/emsdk/emscripten/tag-1.38.22/src/support.js b/emsdk/emscripten/tag-1.38.22/src/support.js
index cff68fbe2..3a4e51dca 100644
--- a/emsdk/emscripten/tag-1.38.22/src/support.js
+++ b/emsdk/emscripten/tag-1.38.22/src/support.js
@@ -211,9 +211,21 @@ function loadWebAssemblyModule(binary, loadAsync) {
       if (prop.startsWith('invoke_')) {
         // A missing invoke, i.e., an invoke for a function type
         // present in the dynamic library but not in the main JS,
-        // and the dynamic library cannot provide JS for it. Use
-        // the generic "X" invoke for it.
-        return env[prop] = invoke_X;
+        // and the dynamic library cannot provide JS for it. Generate
+        // a closure for it.
+        var dynCallName = 'dynCall_' + prop.slice(7);
+        env[prop] = function() {
+          var sp = stackSave();
+          try {
+            var args = Array.prototype.slice.call(arguments);
+            return Module[dynCallName].apply(null, args);
+          } catch(e) {
+            stackRestore(sp);
+            if (typeof e !== 'number' && e !== 'longjmp') throw e;
+            Module["setThrew"](1, 0);
+          }
+        }
+        return env[prop];
       }
       // if not a global, then a function - call it indirectly
       return env[prop] = function() {