diff --git a/api/groups.js b/api/groups.js
index 7fb654f..b01348a 100644
--- a/api/groups.js
+++ b/api/groups.js
@@ -25,8 +25,9 @@ class MarathonApiGroupEndpoints {
   }
 
   async update (groupId, data, force) {
-    const params = new URLSearchParams([['force', force]])
-    const { data: result } = await this.client.put(groupId, { json: data }, { params })
+    const params = new URLSearchParams([['force', !!force]])
+    const path = encodeURIComponent(groupId)
+    const { data: result } = await this.client.put(path, data, { params })
     return result
   }
 
diff --git a/package.json b/package.json
index e9b0f87..3c943ac 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "marathon-node",
-  "version": "2.0.1",
+  "version": "2.0.2",
   "description": "Node.js client library for Mesos Marathon's REST API",
   "main": "index.js",
   "scripts": {