diff --git a/.travis.yml b/.travis.yml
index f291b2876..e2b4f6737 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,6 +18,17 @@ install:
 - pip install coverage  # for code coverage
 - pip install -r monkey/infection_monkey/requirements.txt  # for unit tests
 
+# node + npm + eslint
+- node --version
+- npm --version
+# Install NVM, see https://github.com/nvm-sh/nvm#installing-and-updating
+- curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash
+- nvm install node
+- nvm use node
+- npm i -g eslint
+- node --version
+- npm --version
+
 before_script:
 # Set the server config to `testing`. This is required for for the UTs to pass.
 - python monkey/monkey_island/cc/set_server_config.py testing
@@ -49,12 +60,9 @@ script:
 # Check JS code. The npm install must happen AFTER the flake8 because the node_modules folder will cause a lot of errors.
 - cd monkey_island/cc/ui
 - npm i
-- npm i -g eslint
-- cd -
-- cd monkey_island/cc/ui
-- eslint ./src --quiet
+- eslint ./src --quiet  # Test for errors
 - JS_WARNINGS_AMOUNT_UPPER_LIMIT=490
-- eslint ./src --max-warnings $JS_WARNINGS_AMOUNT_UPPER_LIMIT
+- eslint ./src --max-warnings $JS_WARNINGS_AMOUNT_UPPER_LIMIT  # Test for max warnings
 
 after_success:
   # Upload code coverage results to codecov.io, see https://github.com/codecov/codecov-bash for more information
diff --git a/monkey/infection_monkey/monkey.py b/monkey/infection_monkey/monkey.py
index 6b8803a9f..c96599844 100644
--- a/monkey/infection_monkey/monkey.py
+++ b/monkey/infection_monkey/monkey.py
@@ -80,8 +80,12 @@ class InfectionMonkey(object):
         self._default_tunnel = self._opts.tunnel
         self._default_server = self._opts.server
 
-        if self._opts.depth:
+        if self._opts.depth is not None:
             WormConfiguration._depth_from_commandline = True
+            WormConfiguration.depth = self._opts.depth
+            LOG.debug(f"Setting propagation depth from command line")
+        LOG.debug(f"Set propagation depth to {WormConfiguration.depth}")
+
         self._keep_running = True
         self._network = NetworkScanner()
         self._dropper_path = sys.argv[0]