diff --git a/.gitmodules b/.gitmodules
index 4da888e..26e3784 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,9 +1,13 @@
 [submodule "vendor/unittest_js"]
-	path = vendor/unittest_js
-	url = git://github.com/tobie/unittest_js.git
+  path = vendor/unittest_js
+  url = git://github.com/tobie/unittest_js.git
 [submodule "vendor/caja_builder"]
-	path = vendor/caja_builder
-	url = git://github.com/tobie/unittest_js_caja_builder.git
+  path = vendor/caja_builder
+  url = git://github.com/tobie/unittest_js_caja_builder.git
 [submodule "vendor/pdoc"]
   path = vendor/pdoc
-	url = git://github.com/tobie/pdoc.git
+  url = git://github.com/tobie/pdoc.git
+[submodule "vendor/sprockets"]
+  path = vendor/sprockets
+  url = git://github.com/sstephenson/sprockets.git
+
diff --git a/vendor/sprockets b/vendor/sprockets
new file mode 160000
index 0000000..bf47292
--- /dev/null
+++ b/vendor/sprockets
@@ -0,0 +1 @@
+Subproject commit bf472927407df4318705259ef1790718fc96eddc