diff --git a/circle.yml b/circle.yml
index db14bba..e37a53d 100644
--- a/circle.yml
+++ b/circle.yml
@@ -7,7 +7,7 @@ dependencies:
   cache_directories:
     - ~/cmake-3.11.0-Linux-x86_64
   pre:
-    - sudo add-apt-repository ppa:jonathonf/gcc-7.1
+    - sudo add-apt-repository -y ppa:jonathonf/gcc-7.1
     - sudo apt-get update
     - sudo apt-get install gcc-7 g++-7
   override: