diff --git a/toolkit/benchmark/clients/php/composer.json b/toolkit/benchmark/clients/php/composer.json
index 1cb835fb74..881086b1a8 100644
--- a/toolkit/benchmark/clients/php/composer.json
+++ b/toolkit/benchmark/clients/php/composer.json
@@ -1,6 +1,6 @@
 {
     "require": {
-        "google/cloud-pubsub": "^0.6.2",
+        "google/cloud-pubsub": "^0.6.2 || ^0.12.0",
         "google/gax": "^0.23.0",
         "google/proto-client": "^0.23.0"
     }