diff --git a/travis/linux/before_install.sh b/travis/linux/before_install.sh
index 976144c..07490b2 100644
--- a/travis/linux/before_install.sh
+++ b/travis/linux/before_install.sh
@@ -5,6 +5,6 @@ if [ "$TRAVIS_OS_NAME" = "linux" ]; then
     sudo apt-get -qq -y update
     sudo add-apt-repository -r ppa:webupd8team/java -y
     sudo apt-get -qq upgrade -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" --allow-unauthenticated
-    sudo apt-get -qq dist-upgrade -y; 
+    sudo apt-get -qq dist-upgrade -y --allow-unauthenticated
     export CPU_NUM=$(egrep -c "^processor\s:\s[0-9]+$" /proc/cpuinfo);
 fi