diff --git a/bin/migrate_mongodb_flatten_opdata b/bin/migrate_mongodb_flatten_opdata
new file mode 100755
index 00000000..35b47c00
--- /dev/null
+++ b/bin/migrate_mongodb_flatten_opdata
@@ -0,0 +1,24 @@
+#!/usr/bin/env node
+
+# The MongoDb driver used to create an unnecessary "opData" key in op documents.
+# Future ops now do not create this key. This script fixes all existing ops.
+
+require('coffee-script');
+
+var createdb = require('../src/server/db');
+var options = require('./options');
+if (options.db.type !== 'mongo') {
+  console.error('You must configure your server to use mongodb before using this script');
+  process.exit(1);
+}
+
+var db = createdb(options.db);
+db.migrateFlattenOpData(function(error) {
+  if(error) {
+    throw new Error(error.toString());
+  } else {
+    console.log("DB migrated successfully");
+  }
+  db.close();
+});
+
diff --git a/src/server/db/mongo.coffee b/src/server/db/mongo.coffee
index 4168726f..e8ba1181 100644
--- a/src/server/db/mongo.coffee
+++ b/src/server/db/mongo.coffee
@@ -107,7 +107,17 @@ module.exports = MongoDb = (options) ->
         console.warn "failed to get ops for #{docName}: #{err}" if err
         return callback? err if err
 
-        callback? null, (doc.opData for doc in docs)
+        result = []
+        for doc in docs
+          # This is to support an old schema where ops were stored within an
+          # "opData" object.
+          if doc.opData
+            result.push doc.opData
+          else
+            delete doc._id
+            result.push doc
+
+        callback? null, result
         
   # Write an op to a document.
   #
@@ -125,9 +135,8 @@ module.exports = MongoDb = (options) ->
       return callback? err if err
       
       doc = 
-        opData:
-          op: opData.op
-          meta: opData.meta
+        op: opData.op
+        meta: opData.meta
       
       if options.opsCollectionPerDoc
         doc._id = opData.v
@@ -201,6 +210,37 @@ module.exports = MongoDb = (options) ->
               opsCollection.remove { '_id.doc': docName }, (err, count) ->
                 callback? err
 
+  flattenOpDataCollection = (name, callback) ->
+    client.collection name, (err, collection) ->
+      collection.update {}, {$rename: {"opData.op": "op", "opData.meta": "meta"}}, {multi: true}, (err) ->
+        return callback(err) if err
+        collection.update {}, {$unset: {opData: ""}}, {multi: true}, (err) ->
+          callback(err)
+
+  # A migration to flatten the unnecessary "opdata" key
+  @migrateFlattenOpData = (callback = ->) ->
+    if options.opsCollectionPerDoc
+      client.collection 'docs', (err, docsCollection) ->
+        return callback(err) if err
+
+        docCount = 0
+        docDoneCount = 0
+
+        docsCollection.find({}).each (err, doc) ->
+          return callback(err) if err
+          return if not doc?._id
+          docCount += 1
+          flattenOpDataCollection opsCollectionForDoc(doc._id), (err) ->
+            return callback(err) if err
+            docDoneCount += 1
+            if docDoneCount == docCount
+              callback()
+
+    else
+      flattenOpDataCollection 'ops', callback
+
+
+
   # Close the connection to the database
   @close = ->
     client.close()