diff --git a/common/lib/xmodule/xmodule/capa_module.py b/common/lib/xmodule/xmodule/capa_module.py
index 9d5c85509b..147440f979 100644
--- a/common/lib/xmodule/xmodule/capa_module.py
+++ b/common/lib/xmodule/xmodule/capa_module.py
@@ -651,6 +651,8 @@ class CapaDescriptor(RawDescriptor):
     has_score = True
     template_dir_name = 'problem'
     mako_template = "widgets/problem-edit.html"
+    js = {'coffee': [resource_string(__name__, 'js/src/problem/markdown.coffee')]}
+    js_module_name = "MarkdownEditingDescriptor"
 
     # Capa modules have some additional metadata:
     # TODO (vshnayder): do problems have any other metadata?  Do they
diff --git a/common/lib/xmodule/xmodule/js/src/problem/markdown.coffee b/common/lib/xmodule/xmodule/js/src/problem/markdown.coffee
new file mode 100644
index 0000000000..6a0c0c0e64
--- /dev/null
+++ b/common/lib/xmodule/xmodule/js/src/problem/markdown.coffee
@@ -0,0 +1,10 @@
+class @MarkdownEditingDescriptor extends XModule.Descriptor
+  constructor: (@element) ->
+    @edit_box = CodeMirror.fromTextArea($(".edit-box", @element)[0], {
+      mode: "xml"
+      lineNumbers: true
+      lineWrapping: true
+    })
+
+  save: ->
+    data: @edit_box.getValue()