diff --git a/.travis.sh b/.travis.sh
index 1047c33c..3ed695c0 100644
--- a/.travis.sh
+++ b/.travis.sh
@@ -114,7 +114,7 @@ apt-get update -qq && apt-get install -y -q wget sudo lsb-release gnupg # for do
 echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selections
 travis_time_end
 
-if [ $TEST == "catkin_lint" ]; then
+if [ "$TEST" == "catkin_lint" ]; then
 
     travis_time_start catkin_lint.script
     apt-get install -y -q python-pip
@@ -125,7 +125,7 @@ if [ $TEST == "catkin_lint" ]; then
     ROS_DISTRO=melodic catkin_lint --resolve-env --strict $CI_SOURCE_PATH
 
 
-elif [ $TEST == "clang-format" ]; then
+elif [ "$TEST" == "clang-format" ]; then
 
     travis_time_start clang_format.script
     apt-get install -y -q clang-format-3.9 git
@@ -134,7 +134,7 @@ elif [ $TEST == "clang-format" ]; then
     git -C $CI_SOURCE_PATH --no-pager diff
     git -C $CI_SOURCE_PATH diff-index --quiet HEAD -- .
 
-elif [ $TEST == "clang-tidy" ]; then
+elif [ "$TEST" == "clang-tidy" ]; then
 
     setup