diff --git a/.travis.yml b/.travis.yml
index b5cf62067..732ec7584 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,31 +1,38 @@
 language: python
 matrix:
   include:
+    - os: osx
+      language: generic
+      env: PYTHON_INSTALLER=pyenv TRAVIS_PYTHON_VERSION=2.7.14
+    - os: osx
+      language: generic
+      env: PYTHON_INSTALLER=pyenv TRAVIS_PYTHON_VERSION=3.6.4
+    - os: osx
+      language: generic
+      env:
+        - PYTHON_INSTALLER=brew
+        - PIP_USER_FLAG="--user"
     - os: linux
       python: 2.7
     - os: linux
-      python: 3.4
+      python: 3.4   # When support for 3.4 is removed unpin the PyYAML version below.
     - os: linux
       python: 3.5
     - os: linux
       python: 3.6
-    - os: osx
-      language: generic
-      env: PYTHON_INSTALLER=brew
-    - os: osx
-      language: generic
-      env: PYTHON_INSTALLER=pyenv TRAVIS_PYTHON_VERSION=2.7.14
-    - os: osx
-      language: generic
-      env: PYTHON_INSTALLER=pyenv TRAVIS_PYTHON_VERSION=3.6.4
+    - os: linux
+      python: 3.7
+    - os: linux
+      python: 3.8
 
 # command to install dependencies
 install:
   - source .travis/install.sh
   - python --version
-  - python -m pip install PyYAML argparse rospkg vcstools catkin_pkg python-dateutil rosdistro
-  - python -m pip install -e .
-  - python -m pip install nose coverage flake8 mock codecov
+  - if [ $TRAVIS_PYTHON_VERSION == "3.4" ]; then python -m pip install PyYAML==5.2; fi # Forcing PyYAML 5.2 while we retain Python 3.4 support PyYAML 5.3 and higher does not support Python 3.4
+  - python -m pip install $PIP_USER_FLAG PyYAML argparse rospkg vcstools catkin_pkg python-dateutil rosdistro
+  - python -m pip install $PIP_USER_FLAG -e .
+  - python -m pip install $PIP_USER_FLAG nose coverage flake8 mock codecov
 # command to run tests
 script:
   - python -m nose --with-coverage --cover-package=rosdep2 --with-xunit test
diff --git a/test/test_rosdep_lookup.py b/test/test_rosdep_lookup.py
index 30f26877a..e4648e51c 100644
--- a/test/test_rosdep_lookup.py
+++ b/test/test_rosdep_lookup.py
@@ -58,14 +58,14 @@ def create_test_SourcesListLoader():
 def get_cache_raw():
     cache_rosdep_path = os.path.join(get_cache_dir(), '0a12d6e7b0d47be9b76e7726720e4cb79528cbaa')
     with open(cache_rosdep_path) as f:
-        cache_raw = yaml.load(f.read())
+        cache_raw = yaml.safe_load(f.read())
     return cache_raw
 
 
 def get_cache_raw_python():
     cache_rosdep_path = os.path.join(get_cache_dir(), 'f6f4ef95664e373cd4754501337fa217f5b55d91')
     with open(cache_rosdep_path) as f:
-        cache_raw = yaml.load(f.read())
+        cache_raw = yaml.safe_load(f.read())
     return cache_raw
 
 
@@ -125,7 +125,7 @@ def test_RosdepDefinition():
         pass
 
     #  - test w/valid data
-    d2 = yaml.load(FAKE_TINYXML_RULE)['testtinyxml']
+    d2 = yaml.safe_load(FAKE_TINYXML_RULE)['testtinyxml']
     definition = RosdepDefinition('d2', d2, 'file2.txt')
     #  - tripwire
     str(definition)