diff --git a/scripts/install.sh b/scripts/install.sh
index 93e4981..b2dd3c5 100644
--- a/scripts/install.sh
+++ b/scripts/install.sh
@@ -4,13 +4,9 @@
 HOME_DIR="/home/ubuntu"
 PROJECT_DIR="/vagrant"
 
-if $CI
-then
-    echo $CI
+if [[ "$CI" == "true" ]]; then
     echo "HOME_DIR='$HOME'" >> .bashrc
     echo "PROJECT_DIR='$TRAVIS_BUILD_DIR'" >> .bashrc
-    echo $HOME_DIR
-    echo $PROJECT_DIR
 else
     echo 'HOME_DIR="/home/ubuntu"' >> .bashrc
     echo 'PROJECT_DIR="/vagrant"' >> .bashrc
diff --git a/scripts/install_django_server.sh b/scripts/install_django_server.sh
index d5483c7..dd2d4f7 100644
--- a/scripts/install_django_server.sh
+++ b/scripts/install_django_server.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # Back-end ressources installation
 
-if $CI
+if [[ "$CI" == "true" ]]; then
 then
     PYTHON=python3
     PROJECT_DIR=$TRAVIS_BUILD_DIR
@@ -14,7 +14,7 @@ DJANGO_DIR=$PROJECT_DIR/src/server/django_rest
 echo "DJANGO_DIR='$DJANGO_DIR'" >> .bashrc
 source .bashrc
 
-if ! $CI
+if [[ "$CI" != "true" ]]; then
 then
     sudo apt-get install -y python3.5
 fi
diff --git a/scripts/install_front_end.sh b/scripts/install_front_end.sh
index de3621d..07d65d8 100644
--- a/scripts/install_front_end.sh
+++ b/scripts/install_front_end.sh
@@ -2,7 +2,7 @@
 # Front-end ressources installation
 
 HOME_DIR="/home/ubuntu"
-if $CI
+if [[ "$CI" == "true" ]]; then
 then
     PROJECT_DIR=$TRAVIS_BUILD_DIR
 else
@@ -20,7 +20,7 @@ sudo apt-get install -y nodejs
 
 # Fix error with shared folder and npm modules
 # https://medium.com/@dtinth/isolating-node-modules-in-vagrant-9e646067b36
-if ! $CI
+if [[ "$CI" != "true" ]]; then
 then
     mkdir $HOME_DIR/vagrant_node_modules
     mkdir $PROJECT_DIR/node_modules
diff --git a/scripts/install_opencv.sh b/scripts/install_opencv.sh
index 4ba115a..c3a59df 100644
--- a/scripts/install_opencv.sh
+++ b/scripts/install_opencv.sh
@@ -38,7 +38,7 @@ sudo make install
 sudo ldconfig
 
 cd ~/
-if $CI
+if [[ "$CI" == "true" ]]; then
 then
     echo "export PYTHONPATH=$PYTHONPATH:~/virtualenv/python3.5/site-packages" >> \
         .bashrc