diff --git a/roles/bootstrap-os/tasks/bootstrap-centos.yml b/roles/bootstrap-os/tasks/bootstrap-centos.yml
index 1b5224f34..3e74e0d37 100644
--- a/roles/bootstrap-os/tasks/bootstrap-centos.yml
+++ b/roles/bootstrap-os/tasks/bootstrap-centos.yml
@@ -30,6 +30,7 @@
 - name: Add proxy to /etc/yum.conf if http_proxy is defined
   lineinfile:
     path: "/etc/yum.conf"
+    regexp: "^proxy=.*$"
     line: "proxy={{ http_proxy }}"
     create: true
     state: present