diff --git a/lib/activations.js b/lib/activations.js
index 27f1ad4..d0b62d9 100644
--- a/lib/activations.js
+++ b/lib/activations.js
@@ -7,7 +7,7 @@
   list (options) {
     const namespace = this.namespace(options)
     const params = this.params('GET', `namespaces/${namespace}/activations`)
-    params.qs = this.qs(options || {}, ['name', 'skip', 'limit', 'upto', 'docs'])
+    params.qs = this.qs(options || {}, ['name', 'skip', 'limit', 'upto', 'docs', 'since'])
     return this.request(params)
   }