diff --git a/.travis.yml b/.travis.yml
index e5cd462c9..4de85a20e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -58,12 +58,18 @@ matrix:
         - env: TOXENV='py35-numpy11'
         - env: TOXENV='py36-numpy12'
 
+        # test against oldest compatible versions of all dependencies
+        - env: TOXENV='py35-legacy'
+
         # also test against development versions of Astropy and GWCS
         - env: TOXENV='py37-astrodev'
 
         # Test against development version of numpy (this job can fail)
         - env: TOXENV='py37-numpydev'
 
+        # Test against prerelease versions of all dependencies
+        - env: TOXENV='prerelease'
+
         # Try a run on OSX
         - os: osx
           env: TOXENV='py37-stable'
@@ -87,8 +93,8 @@ matrix:
         # Py37 on Windows at the moment
         - os: windows
           env: TOXENV='py37-stable' TOX_ARGS='--remote-data'
-
         - env: TOXENV='py37-numpydev'
+        - env: TOXENV='prerelease'
 
 install:
     - git clone git://github.com/astropy/ci-helpers.git
diff --git a/asdf/conftest.py b/asdf/conftest.py
index 3e5559b68..916b88a7c 100644
--- a/asdf/conftest.py
+++ b/asdf/conftest.py
@@ -4,8 +4,6 @@
 # by importing them here in conftest.py they are discoverable by py.test
 # no matter how it is invoked within the source tree.
 
-from astropy.tests.plugins.display import PYTEST_HEADER_MODULES, TESTED_VERSIONS
-
 import os
 
 import pytest
@@ -17,21 +15,6 @@
 from . import version
 from .tests.httpserver import HTTPServer, RangeHTTPServer
 
-packagename = os.path.basename(os.path.dirname(__file__))
-TESTED_VERSIONS[packagename] = version.version
-
-
-try:
-    PYTEST_HEADER_MODULES['Astropy'] = 'astropy'
-    PYTEST_HEADER_MODULES['jsonschema'] = 'jsonschema'
-    PYTEST_HEADER_MODULES['pyyaml'] = 'yaml'
-    PYTEST_HEADER_MODULES['six'] = 'six'
-    del PYTEST_HEADER_MODULES['h5py']
-    del PYTEST_HEADER_MODULES['Matplotlib']
-    del PYTEST_HEADER_MODULES['Scipy']
-except (NameError, KeyError):
-    pass
-
 
 @pytest.fixture()
 def httpserver(request):
diff --git a/conftest.py b/conftest.py
index 40135efeb..76c9e5692 100644
--- a/conftest.py
+++ b/conftest.py
@@ -14,7 +14,7 @@
                                     ('asdf', 'asdf'),
                                     ('numpy', 'numpy'),
                                     ('jsonschema', 'jsonschema'),
-                                    ('pyyaml', 'pyyaml'),
+                                    ('pyyaml', 'yaml'),
                                     ('astropy', 'astropy')])
 
 try:
diff --git a/tox.ini b/tox.ini
index e203f4260..25afee6e4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,7 @@
 [tox]
 envlist =
     {py36,py37}-{stable,gwcsdev},py37-astrodev
+    py35-legacy
 
 [testenv]
 deps=
@@ -13,6 +14,10 @@ deps=
     py35-!astrodev,py36-!astrodev: gwcs~=0.9.1
     py37-!astrodev: gwcs
     numpydev: git+git://github.com/numpy/numpy
+    legacy: semantic_version==2.3.1
+    legacy: pyyaml==3.10
+    legacy: jsonschema==2.3
+    legacy: numpy~=1.10.0
 conda_deps=
     pytest
     !astrodev: astropy
@@ -26,6 +31,10 @@ commands=
     astrodev: pip install --no-deps git+git://github.com/spacetelescope/gwcs
     pytest {posargs}
 
+[testenv:prerelease]
+basepython= python3.7
+pip_pre= true
+
 [testenv:egg_info]
 deps=
 conda_deps=