diff --git a/.circleci/config.yml b/.circleci/config.yml
index 46832cd..cfcd07d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -3,6 +3,9 @@
 
 # For a detailed guide to building and testing on iOS, read the docs:
 # https://circleci.com/docs/testing-ios/
+on:
+   pull_request:
+      types: [opened, reopened]
 version: 2.1
 
 # Define a job to be invoked later in a workflow.