diff --git a/emsdk_manifest.json b/emsdk_manifest.json
index 301aebc..014308d 100644
--- a/emsdk_manifest.json
+++ b/emsdk_manifest.json
@@ -139,7 +139,8 @@
     "windows_url": "emscripten-clang_e1.21.0.zip",
     "osx_url": "emscripten-clang_e1.21.0.tar.gz",
     "activated_path": "%installation_dir%",
-    "activated_cfg": "LLVM_ROOT='%installation_dir%'"
+    "activated_cfg": "LLVM_ROOT='%installation_dir%'",
+    "is_old": true
   },
   {
     "id": "clang",
@@ -388,7 +389,8 @@
     "unix_url": "emscripten-1.21.0.tar.gz",
     "activated_cfg": "EMSCRIPTEN_ROOT='%installation_dir%'",
     "activated_path": "%installation_dir%",
-    "activated_env": "EMSCRIPTEN=%installation_dir%"
+    "activated_env": "EMSCRIPTEN=%installation_dir%",
+    "is_old": true
   },
   {
     "id": "emscripten",
@@ -738,13 +740,15 @@
     "version": "1.21.0",
     "bitness": 64,
     "uses": ["clang-e1.21.0-64bit", "node-0.10.17-64bit", "python-2.7.5.3-64bit", "emscripten-1.21.0"],
-    "os": "win"
+    "os": "win",
+    "is_old": true
   },
   {
     "version": "1.21.0",
     "bitness": 64,
     "uses": ["clang-e1.21.0-64bit", "node-0.10.18-64bit", "emscripten-1.21.0"],
-    "os": "osx"
+    "os": "osx",
+    "is_old": true
   },
   {
     "version": "1.22.0",