diff --git a/setup-fortran.sh b/setup-fortran.sh
index 3a59907..d3747b0 100755
--- a/setup-fortran.sh
+++ b/setup-fortran.sh
@@ -43,7 +43,7 @@ install_gcc_brew()
 
 install_gcc_apt()
 {
-  sudo add-apt-repository ppa:ubuntu-toolchain-r/test
+  sudo add-apt-repository --yes ppa:ubuntu-toolchain-r/test
   sudo apt-get update
   sudo apt-get install -y gcc-${version} gfortran-${version}
   sudo update-alternatives \