diff --git a/emsdk_manifest.json b/emsdk_manifest.json
index 88ababe..0036d1f 100644
--- a/emsdk_manifest.json
+++ b/emsdk_manifest.json
@@ -142,6 +142,24 @@
     "activated_env": "JAVA_HOME=%installation_dir%",
     "activated_cfg": "JAVA='%installation_dir%/bin/java%.exe%'"
   },
+  {
+    "id": "spidermonkey",
+    "version": "27.0.1",
+    "bitness": 64,
+    "windows_url": "spidermonkey-27.0.1.zip",
+    "osx_url": "spidermonkey-27.0.1.tar.gz",
+    "activated_path": "%installation_dir%",
+    "activated_cfg": "SPIDERMONKEY_ENGINE='%installation_dir%/js%.exe%'"
+  },
+  {
+    "id": "spidermonkey",
+    "version": "nightly-2014-03-13",
+    "bitness": 64,
+    "windows_url": "spidermonkey-nightly-2014-03-13.zip",
+    "osx_url": "spidermonkey-nightly-2014-03-13.tar.gz",
+    "activated_path": "%installation_dir%",
+    "activated_cfg": "SPIDERMONKEY_ENGINE='%installation_dir%/js%.exe%'"
+  },
   {
     "id": "git",
     "version": "1.8.3",