diff --git a/scripts/install b/scripts/install
index 7d84ce7..bd2342e 100644
--- a/scripts/install
+++ b/scripts/install
@@ -190,10 +190,9 @@ mkdir -p "$final_path/db"
 chown -R "$app":"$app" "$final_path"
 pushd $final_path
     ynh_use_nodejs
-    sudo -u $app env PATH=$PATH:$nodejs_path npm install hoek@^4.2.1 --save --production
-    sudo -u $app env PATH=$PATH:$nodejs_path npm install ts-node --save --production
-    sudo -u $app env PATH=$PATH:$nodejs_path npm install --production
-    sudo -u $app env PATH=$PATH:$nodejs_path npm audit fix
+    #sudo -u $app env PATH=$PATH:$nodejs_path npm install hoek@^4.2.1 --save --production
+    sudo -u $app env PATH=$PATH:$nodejs_path yarn install ts-node --save --production
+    sudo -u $app env PATH=$PATH:$nodejs_path yarn install --production
 popd
 
 #=================================================
diff --git a/scripts/remove b/scripts/remove
index 529f5ef..0ad888e 100644
--- a/scripts/remove
+++ b/scripts/remove
@@ -102,9 +102,6 @@ fi
 # REMOVE THE CRON FILE
 #=================================================
 
-#npm uninstall -g ts-node
-#npm uninstall -g typescript
-
 # Remove a cron file
 #ynh_secure_remove "/etc/cron.d/$app"
 
diff --git a/scripts/upgrade b/scripts/upgrade
index 3e795f1..c8e8a08 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -139,9 +139,8 @@ mkdir -p "$final_path/db"
 chown -R "$app":"$app" "$final_path"
 pushd $final_path
     ynh_use_nodejs
-    sudo -u $app env PATH=$PATH:$nodejs_path npm update --production
-    sudo -u $app env PATH=$PATH:$nodejs_path npm install --production
-    sudo -u $app env PATH=$PATH:$nodejs_path npm audit fix
+    sudo -u $app env PATH=$PATH:$nodejs_path yarn update --production
+    sudo -u $app env PATH=$PATH:$nodejs_path yarn install --production
 popd
 
 ### Verify the checksum of a file, stored by `ynh_store_file_checksum` in the install script.