diff --git a/package.json b/package.json
index cf6234396..e2fed6ef1 100644
--- a/package.json
+++ b/package.json
@@ -31,6 +31,7 @@
     "pouchdb-adapter-leveldb": "^6.0.4",
     "pouchdb-adapter-memory": "^6.0.4",
     "pouchdb-core": "^6.0.4",
+    "pouchdb-mapreduce": "^6.0.6",
     "rc": "^1.1.6",
     "semver": "^5.1.0",
     "yargs": "^6.0.0"
diff --git a/server/index.js b/server/index.js
index 7aa3db7b0..e2d250cb1 100644
--- a/server/index.js
+++ b/server/index.js
@@ -20,6 +20,9 @@ function register (server, options, next) {
     options.db = {}
   }
 
+  // mapreduce is required for `db.query()`
+  PouchDB.plugin(require('pouchdb-mapreduce'))
+
   if (!options.db.url) {
     if (options.inMemory) {
       PouchDB.plugin(require('pouchdb-adapter-memory'))