diff --git a/.travis.yml b/.travis.yml
index 72669d3d..74ac30de 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,6 +10,7 @@ sudo: false
 branches:
   only:
   - master
+  - /^v\d+\.\d+(\.\d+)?(-\S*)?$/
 before_install:
 - wget https://github.com/mozilla/geckodriver/releases/download/v0.21.0/geckodriver-v0.21.0-linux64.tar.gz
 - mkdir geckodriver
diff --git a/CHANGELOG b/CHANGELOG
index b9b1de7b..aff6d4ef 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+v0.9.3 (02/14/19)
+* PageLoadError and WrongPageError now inherit WebDriverException so
+  they can trigger retries instead of immediately failing tests
+
 v0.9.2 (11/20/18) (0.9.1 skipped due to PyPI deployment issue)
 * Support passing additional desired capabilities to remote WebDriver instances.
 
diff --git a/bok_choy/a11y/a11y_audit.py b/bok_choy/a11y/a11y_audit.py
index f48cf6fa..64656efc 100644
--- a/bok_choy/a11y/a11y_audit.py
+++ b/bok_choy/a11y/a11y_audit.py
@@ -133,7 +133,7 @@ def _get_rules_js(self):
         Raises: `RuntimeError` if the file isn't found.
         """
         if not os.path.isfile(self.config.rules_file):
-            msg = 'Could not find the accessibility tools JS file: {}'.format(
+            msg = u'Could not find the accessibility tools JS file: {}'.format(
                 self.config.rules_file)
             raise RuntimeError(msg)
 
diff --git a/bok_choy/a11y/axe_core_ruleset.py b/bok_choy/a11y/axe_core_ruleset.py
index d94eff71..c7c92ac0 100644
--- a/bok_choy/a11y/axe_core_ruleset.py
+++ b/bok_choy/a11y/axe_core_ruleset.py
@@ -24,7 +24,7 @@ class AxeCoreAuditConfig(A11yAuditConfig):
     def __init__(self, *args, **kwargs):
         super(AxeCoreAuditConfig, self).__init__(*args, **kwargs)
         self.rules, self.context = None, None
-        self.custom_rules = "customRules={}"
+        self.custom_rules = u"customRules={}"
         self.rules_file = os.path.join(
             os.path.split(CUR_DIR)[0],
             'vendor/axe-core/axe.min.js'
@@ -243,7 +243,7 @@ def _check_rules(browser, rules_js, config):
         __Caution__: You probably don't really want to call this method
         directly! It will be used by `AxeCoreAudit.do_audit`.
         """
-        audit_run_script = dedent("""
+        audit_run_script = dedent(u"""
             {rules_js}
             {custom_rules}
             axe.configure(customRules);
@@ -259,7 +259,7 @@ def _check_rules(browser, rules_js, config):
             options=config.rules
         )
 
-        audit_results_script = dedent("""
+        audit_results_script = dedent(u"""
             window.console.log(window.a11yAuditResults);
             return window.a11yAuditResults;
         """)
@@ -350,14 +350,14 @@ def _get_message(node):
 
         lines = []
         for error_type in errors:
-            lines.append("Severity: {}".format(error_type.get("impact")))
-            lines.append("Rule ID: {}".format(error_type.get("id")))
-            lines.append("Help URL: {}\n".format(error_type.get('helpUrl')))
+            lines.append(u"Severity: {}".format(error_type.get("impact")))
+            lines.append(u"Rule ID: {}".format(error_type.get("id")))
+            lines.append(u"Help URL: {}\n".format(error_type.get('helpUrl')))
 
             for node in error_type['nodes']:
-                msg = "Message: {}".format(_get_message(node))
-                html = "Html: {}".format(node.get('html').encode('utf-8'))
-                target = "Target: {}".format(node.get('target'))
+                msg = u"Message: {}".format(_get_message(node))
+                html = u"Html: {}".format(node.get('html').encode('utf-8'))
+                target = u"Target: {}".format(node.get('target'))
                 fill_opts = {
                     'width': 100,
                     'initial_indent': '\t',
@@ -382,7 +382,7 @@ def report_errors(audit, url):
         """
         errors = AxeCoreAudit.get_errors(audit)
         if errors["total"] > 0:
-            msg = "URL '{}' has {} errors:\n\n{}".format(
+            msg = u"URL '{}' has {} errors:\n\n{}".format(
                 url,
                 errors["total"],
                 AxeCoreAudit.format_errors(errors["errors"])
diff --git a/bok_choy/a11y/axs_ruleset.py b/bok_choy/a11y/axs_ruleset.py
index ef86e401..4806f600 100644
--- a/bok_choy/a11y/axs_ruleset.py
+++ b/bok_choy/a11y/axs_ruleset.py
@@ -90,8 +90,8 @@ def set_scope(self, include=None, exclude=None):
                 page.a11y_audit.config.set_scope()
         """
         if include:
-            self.scope = "document.querySelector(\"{}\")".format(
-                ', '.join(include)
+            self.scope = u"document.querySelector(\"{}\")".format(
+                u', '.join(include)
             )
         else:
             self.scope = "null"
@@ -160,7 +160,7 @@ def _check_rules(browser, rules_js, config):
         # run all rules.
         rules = config.rules_to_run
         if rules:
-            rules_config = "auditConfig.auditRulesToRun = {rules};".format(
+            rules_config = u"auditConfig.auditRulesToRun = {rules};".format(
                 rules=rules)
         else:
             rules_config = ""
@@ -168,12 +168,12 @@ def _check_rules(browser, rules_js, config):
         ignored_rules = config.rules_to_ignore
         if ignored_rules:
             rules_config += (
-                "\nauditConfig.auditRulesToIgnore = {rules};".format(
+                u"\nauditConfig.auditRulesToIgnore = {rules};".format(
                     rules=ignored_rules
                 )
             )
 
-        script = dedent("""
+        script = dedent(u"""
             {rules_js}
             var auditConfig = new axs.AuditConfiguration();
             {rules_config}
@@ -219,9 +219,9 @@ def report_errors(audit, url):
         """
         errors = AxsAudit.get_errors(audit)
         if errors:
-            msg = "URL '{}' has {} errors:\n{}".format(
+            msg = u"URL '{}' has {} errors:\n{}".format(
                 url,
                 len(errors),
-                (', ').join(errors)
+                ', '.join(errors)
             )
             raise AccessibilityError(msg)
diff --git a/bok_choy/browser.py b/bok_choy/browser.py
index e239f77c..7d6e1aca 100644
--- a/bok_choy/browser.py
+++ b/bok_choy/browser.py
@@ -100,7 +100,7 @@ def save_source(driver, name):
         with open(file_name, 'wb') as output_file:
             output_file.write(source.encode('utf-8'))
     except Exception:  # pylint: disable=broad-except
-        msg = "Could not save the browser page source to {}.".format(file_name)
+        msg = u"Could not save the browser page source to {}.".format(file_name)
         LOGGER.warning(msg)
 
 
@@ -131,8 +131,8 @@ def save_screenshot(driver, name):
 
     else:
         msg = (
-            "Browser does not support screenshots. "
-            "Could not save screenshot '{name}'"
+            u"Browser does not support screenshots. "
+            u"Could not save screenshot '{name}'"
         ).format(name=name)
 
         LOGGER.warning(msg)
@@ -182,8 +182,8 @@ def save_driver_logs(driver, prefix):
                     output_file.write("{}{}".format(dumps(line), '\n'))
         except:  # pylint: disable=bare-except
             msg = (
-                "Could not save browser log of type '{log_type}'. "
-                "It may be that the browser does not support it."
+                u"Could not save browser log of type '{log_type}'. "
+                u"It may be that the browser does not support it."
             ).format(log_type=log_type)
 
             LOGGER.warning(msg, exc_info=True)
@@ -311,22 +311,22 @@ def _firefox_profile():
     profile_dir = os.environ.get(FIREFOX_PROFILE_ENV_VAR)
 
     if profile_dir:
-        LOGGER.info("Using firefox profile: %s", profile_dir)
+        LOGGER.info(u"Using firefox profile: %s", profile_dir)
         try:
             firefox_profile = webdriver.FirefoxProfile(profile_dir)
         except OSError as err:
             if err.errno == errno.ENOENT:
                 raise BrowserConfigError(
-                    "Firefox profile directory {env_var}={profile_dir} does not exist".format(
+                    u"Firefox profile directory {env_var}={profile_dir} does not exist".format(
                         env_var=FIREFOX_PROFILE_ENV_VAR, profile_dir=profile_dir))
             elif err.errno == errno.EACCES:
                 raise BrowserConfigError(
-                    "Firefox profile directory {env_var}={profile_dir} has incorrect permissions. It must be \
+                    u"Firefox profile directory {env_var}={profile_dir} has incorrect permissions. It must be \
                     readable and executable.".format(env_var=FIREFOX_PROFILE_ENV_VAR, profile_dir=profile_dir))
             else:
                 # Some other OSError:
                 raise BrowserConfigError(
-                    "Problem with firefox profile directory {env_var}={profile_dir}: {msg}"
+                    u"Problem with firefox profile directory {env_var}={profile_dir}: {msg}"
                     .format(env_var=FIREFOX_PROFILE_ENV_VAR, profile_dir=profile_dir, msg=str(err)))
     else:
         LOGGER.info("Using default firefox profile")
@@ -373,14 +373,14 @@ def _local_browser_class(browser_name):
     """
 
     # Log name of local browser
-    LOGGER.info("Using local browser: %s [Default is firefox]", browser_name)
+    LOGGER.info(u"Using local browser: %s [Default is firefox]", browser_name)
 
     # Get class of local browser based on name
     browser_class = BROWSERS.get(browser_name)
     headless = os.environ.get('BOKCHOY_HEADLESS', 'false').lower() == 'true'
     if browser_class is None:
         raise BrowserConfigError(
-            "Invalid browser name {name}.  Options are: {options}".format(
+            u"Invalid browser name {name}.  Options are: {options}".format(
                 name=browser_name, options=", ".join(list(BROWSERS.keys()))))
     else:
         if browser_name == 'firefox':
@@ -392,7 +392,7 @@ def _local_browser_class(browser_name):
             firefox_options = FirefoxOptions()
             firefox_options.log.level = 'trace'
             if headless:
-                firefox_options.set_headless(True)
+                firefox_options.headless = True
             browser_args = []
             browser_kwargs = {
                 'firefox_profile': _firefox_profile(),
@@ -418,7 +418,7 @@ def _local_browser_class(browser_name):
         elif browser_name == 'chrome':
             chrome_options = ChromeOptions()
             if headless:
-                chrome_options.set_headless(True)
+                chrome_options.headless = True
 
             # Emulate webcam and microphone for testing purposes
             chrome_options.add_argument('--use-fake-device-for-media-stream')
@@ -429,7 +429,7 @@ def _local_browser_class(browser_name):
 
             browser_args = []
             browser_kwargs = {
-                'chrome_options': chrome_options,
+                'options': chrome_options,
             }
         else:
             browser_args, browser_kwargs = [], {}
@@ -453,14 +453,14 @@ def _remote_browser_class(env_vars, tags=None):
     caps = _capabilities_dict(envs, tags)
 
     if 'accessKey' in caps:
-        LOGGER.info("Using SauceLabs: %s %s %s", caps['platform'], caps['browserName'], caps['version'])
+        LOGGER.info(u"Using SauceLabs: %s %s %s", caps['platform'], caps['browserName'], caps['version'])
     else:
-        LOGGER.info("Using Remote Browser: %s", caps['browserName'])
+        LOGGER.info(u"Using Remote Browser: %s", caps['browserName'])
 
     # Create and return a new Browser
     # We assume that the WebDriver end-point is running locally (e.g. using
     # SauceConnect)
-    url = "http://{0}:{1}/wd/hub".format(
+    url = u"http://{0}:{1}/wd/hub".format(
         envs['SELENIUM_HOST'], envs['SELENIUM_PORT'])
 
     browser_args = []
@@ -532,13 +532,13 @@ def _required_envs(env_vars):
     missing = [key for key, val in list(envs.items()) if val is None]
     if missing:
         msg = (
-            "These environment variables must be set: " + ", ".join(missing)
+            u"These environment variables must be set: " + u", ".join(missing)
         )
         raise BrowserConfigError(msg)
 
     # Check that we support this browser
     if envs['SELENIUM_BROWSER'] not in BROWSERS:
-        msg = "Unsuppported browser: {0}".format(envs['SELENIUM_BROWSER'])
+        msg = u"Unsuppported browser: {0}".format(envs['SELENIUM_BROWSER'])
         raise BrowserConfigError(msg)
 
     return envs
diff --git a/bok_choy/javascript.py b/bok_choy/javascript.py
index 543f4c69..9257afca 100644
--- a/bok_choy/javascript.py
+++ b/bok_choy/javascript.py
@@ -123,14 +123,14 @@ def _wait_for_js(self):
     if hasattr(self, '_js_vars') and self._js_vars:
         EmptyPromise(
             lambda: _are_js_vars_defined(self.browser, self._js_vars),
-            "JavaScript variables defined: {0}".format(", ".join(self._js_vars))
+            u"JavaScript variables defined: {0}".format(", ".join(self._js_vars))
         ).fulfill()
 
     # Wait for RequireJS dependencies to load
     if hasattr(self, '_requirejs_deps') and self._requirejs_deps:
         EmptyPromise(
             lambda: _are_requirejs_deps_loaded(self.browser, self._requirejs_deps),
-            "RequireJS dependencies loaded: {0}".format(", ".join(self._requirejs_deps)),
+            u"RequireJS dependencies loaded: {0}".format(", ".join(self._requirejs_deps)),
             try_limit=5
         ).fulfill()
 
@@ -144,13 +144,13 @@ def _are_js_vars_defined(browser, js_vars):
     """
     # This script will evaluate to True iff all of
     # the required vars are defined.
-    script = " && ".join([
-        "!(typeof {0} === 'undefined')".format(var)
+    script = u" && ".join([
+        u"!(typeof {0} === 'undefined')".format(var)
         for var in js_vars
     ])
 
     try:
-        return browser.execute_script("return {}".format(script))
+        return browser.execute_script(u"return {}".format(script))
     except WebDriverException as exc:
         if "is not defined" in exc.msg or "is undefined" in exc.msg:
             return False
@@ -176,7 +176,7 @@ def _are_requirejs_deps_loaded(browser, deps):
     # We install a RequireJS module with the dependencies we want
     # to ensure are loaded.  When our module loads, we return
     # control to the test suite.
-    script = dedent("""
+    script = dedent(u"""
         // Retrieve the callback function used to return control to the test suite
         var callback = arguments[arguments.length - 1];
 
diff --git a/bok_choy/page_object.py b/bok_choy/page_object.py
index 0c06f55e..42dec0d9 100644
--- a/bok_choy/page_object.py
+++ b/bok_choy/page_object.py
@@ -40,14 +40,14 @@
 XSS_HTML = "<xss"
 
 
-class WrongPageError(Exception):
+class WrongPageError(WebDriverException):
     """
     The page object reports that we're on the wrong page!
     """
     pass
 
 
-class PageLoadError(Exception):
+class PageLoadError(WebDriverException):
     """
     An error occurred while loading the page.
     """
@@ -318,18 +318,18 @@ def visit(self):
             PageObject
         """
         if self.url is None:
-            raise NotImplementedError("Page {} does not provide a URL to visit.".format(self))
+            raise NotImplementedError(u"Page {} does not provide a URL to visit.".format(self))
 
         # Validate the URL
         if not self.validate_url(self.url):
-            raise PageLoadError("Invalid URL: '{}'".format(self.url))
+            raise PageLoadError(u"Invalid URL: '{}'".format(self.url))
 
         # Visit the URL
         try:
             self.browser.get(self.url)
         except (WebDriverException, socket.gaierror):
             LOGGER.warning(u"Unexpected page load exception:", exc_info=True)
-            raise PageLoadError("Could not load page '{!r}' at URL '{}'".format(
+            raise PageLoadError(u"Could not load page '{!r}' at URL '{}'".format(
                 self, self.url
             ))
 
@@ -342,7 +342,7 @@ def visit(self):
         try:
             return self.wait_for_page()
         except BrokenPromise:
-            raise PageLoadError("Timed out waiting to load page '{!r}' at URL '{}'".format(
+            raise PageLoadError(u"Timed out waiting to load page '{!r}' at URL '{}'".format(
                 self, self.url
             ))
 
@@ -389,7 +389,7 @@ def _verify_page(self):
         if not, raise a `WrongPageError`.
         """
         if not self.is_browser_on_page():
-            msg = "Not on the correct page to use '{!r}' at URL '{}'".format(
+            msg = u"Not on the correct page to use '{!r}' at URL '{}'".format(
                 self, self.url
             )
             raise WrongPageError(msg)
@@ -413,7 +413,7 @@ def _verify_xss_exposure(self):
             if all_hits_count > safe_hits_count:
                 potential_hits = re.findall('<[^<]+<xss', html_source)
                 raise XSSExposureError(
-                    "{} XSS issue(s) found on page. Potential places are {}".format(
+                    u"{} XSS issue(s) found on page. Potential places are {}".format(
                         all_hits_count - safe_hits_count, potential_hits
                     )
                 )
@@ -467,7 +467,7 @@ def _is_document_ready():
             ).fulfill()
 
         result = Promise(
-            lambda: (self.is_browser_on_page(), self), "loaded page {!r}".format(self),
+            lambda: (self.is_browser_on_page(), self), u"loaded page {!r}".format(self),
             timeout=timeout
         ).fulfill()
 
@@ -519,7 +519,7 @@ def handle_alert(self, confirm=True):
         """
 
         # Before executing the `with` block, stub the confirm/alert functions
-        script = dedent("""
+        script = dedent(u"""
             window.confirm = function() {{ return {0}; }};
             window.alert = function() {{ return; }};
         """.format("true" if confirm else "false")).strip()
@@ -698,9 +698,9 @@ def scroll_to_element(self, element_selector, timeout=60):
 
         """
         # Ensure element exists
-        msg = "Element '{element}' is present".format(element=element_selector)
+        msg = u"Element '{element}' is present".format(element=element_selector)
         self.wait_for(lambda: self.q(css=element_selector).present, msg, timeout=timeout)
 
         # Obtain coordinates and use those for JavaScript call
         loc = self.q(css=element_selector).first.results[0].location
-        self.browser.execute_script("window.scrollTo({x},{y})".format(x=loc['x'], y=loc['y']))
+        self.browser.execute_script(u"window.scrollTo({x},{y})".format(x=loc['x'], y=loc['y']))
diff --git a/bok_choy/query.py b/bok_choy/query.py
index 698a07ae..364d9c63 100644
--- a/bok_choy/query.py
+++ b/bok_choy/query.py
@@ -97,7 +97,7 @@ def replace(self, **kwargs):
         clone.transforms = list(clone.transforms)
         for key, value in kwargs.items():
             if not hasattr(clone, key):
-                raise TypeError('replace() got an unexpected keyword argument {!r}'.format(key))
+                raise TypeError(u'replace() got an unexpected keyword argument {!r}'.format(key))
 
             setattr(clone, key, value)
         return clone
@@ -342,7 +342,7 @@ def __init__(self, browser, **kwargs):
         query_name, query_value = list(kwargs.items())[0]
 
         if query_name not in QUERY_TYPES:
-            raise TypeError('{} is not a supported query type for BrowserQuery()'.format(query_name))
+            raise TypeError(u'{} is not a supported query type for BrowserQuery()'.format(query_name))
 
         def query_fn():  # pylint: disable=missing-docstring
             return getattr(browser, QUERY_TYPES[query_name])(query_value)
@@ -372,7 +372,7 @@ def attrs(self, attribute_name):
         Returns:
             A list of attribute values for `attribute_name`.
         """
-        desc = 'attrs({!r})'.format(attribute_name)
+        desc = u'attrs({!r})'.format(attribute_name)
         return self.map(lambda el: el.get_attribute(attribute_name), desc).results
 
     @property
@@ -504,4 +504,4 @@ def _fill(elem):  # pylint: disable=missing-docstring
             elem.clear()
             elem.send_keys(text)
 
-        self.map(_fill, 'fill({!r})'.format(text)).execute()
+        self.map(_fill, u'fill({!r})'.format(text)).execute()
diff --git a/bok_choy/web_app_test.py b/bok_choy/web_app_test.py
index 4986f3b0..354eca67 100644
--- a/bok_choy/web_app_test.py
+++ b/bok_choy/web_app_test.py
@@ -112,7 +112,7 @@ def set_viewport_size(self, width, height):
 
         # Measure the difference between the actual document width and the
         # desired viewport width so we can account for scrollbars:
-        script = "return {width: document.body.clientWidth, height: document.body.clientHeight};"
+        script = u"return {width: document.body.clientWidth, height: document.body.clientHeight};"
         measured = self.driver.execute_script(script)
         delta = width - measured['width']
 
diff --git a/requirements/base.in b/requirements/base.in
index 1c26d63b..d0e962aa 100644
--- a/requirements/base.in
+++ b/requirements/base.in
@@ -1,5 +1,7 @@
 # Core requirements for using this application
 
+-c constraints.txt
+
 lazy                      # For lazy evaluation of the page object's a11y_audit attribute
 selenium>=2,<4            # Browser automation driver
 six                       # For Python 2 & 3 compatibility
diff --git a/requirements/base.txt b/requirements/base.txt
index e76924a2..d17c1df6 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -4,7 +4,7 @@
 #
 #    make upgrade
 #
-lazy==1.3
-selenium==3.14.0
-six==1.11.0
-urllib3==1.23             # via selenium
+lazy==1.4
+selenium==3.141.0
+six==1.12.0
+urllib3==1.24.1           # via selenium
diff --git a/requirements/constraints.txt b/requirements/constraints.txt
new file mode 100644
index 00000000..fff6e400
--- /dev/null
+++ b/requirements/constraints.txt
@@ -0,0 +1,15 @@
+# Version constraints for pip-installation.
+#
+# This file doesn't install any packages. It specifies version constraints
+# that will be applied if a package is needed.
+#
+# When pinning something here, please provide an explanation of why.  Ideally,
+# link to other information that will help people in the future to remove the
+# pin when possible.  Writing an issue against the offending project and
+# linking to it here is good.
+
+# more-itertools 6.0.0 dropped Python 2.7 support
+more-itertools<6.0.0
+
+# Newer versions of pylint-plugin-utils drop Python 2.7 support
+pylint-plugin-utils<0.4
diff --git a/requirements/dev.in b/requirements/dev.in
index 95c6cd0a..24511c47 100644
--- a/requirements/dev.in
+++ b/requirements/dev.in
@@ -1,6 +1,8 @@
 # Dependencies that are used in development environments.
 # Please do not use this file for packages that are needed for test runs.
 
+-c constraints.txt
+
 -r pip-tools.txt                    # pip-tools and its dependencies, for managing requirements files
 -r needle.txt                       # Dependencies for running the various test suites
 -r travis.txt                       # Dependencies for tox and related utilities
diff --git a/requirements/dev.txt b/requirements/dev.txt
index 6e47df9b..ec630f93 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -5,57 +5,50 @@
 #    make upgrade
 #
 apipkg==1.5
-astroid==1.5.2
-atomicwrites==1.1.5
-attrs==18.1.0
-backports.functools-lru-cache==1.5
-certifi==2018.4.16
+astroid==1.5.3
+atomicwrites==1.3.0
+attrs==18.2.0
+certifi==2018.11.29
 chardet==3.0.4
 click-log==0.1.8
-click==6.7
+click==7.0
 codecov==2.0.15
-configparser==3.5.0
-coverage==4.5.1
-edx-lint==0.5.5
-enum34==1.1.6
+coverage==4.5.2
+edx-lint==1.1.0
 execnet==1.5.0
-first==2.0.1
-funcsigs==1.0.2
-futures==3.2.0 ; python_version == "2.7"
-idna==2.7
+filelock==3.0.10
+idna==2.8
 isort==4.3.4
 lazy-object-proxy==1.3.1
-lazy==1.3
+lazy==1.4
 mccabe==0.6.1
 mock==2.0.0
-more-itertools==4.3.0
+more-itertools==5.0.0
 needle==0.5.0
 nose==1.3.7
-packaging==17.1
-pathlib2==2.3.2
-pbr==4.2.0
-pillow==5.2.0
-pip-tools==2.0.2
-pluggy==0.7.1
-py==1.5.4
-pycodestyle==2.4.0
+packaging==19.0
+pbr==5.1.2
+pillow==5.4.1
+pip-tools==3.3.2
+pluggy==0.8.1
+py==1.7.0
+pycodestyle==2.5.0
 pylint-celery==0.3
 pylint-django==0.7.2
 pylint-plugin-utils==0.3
-pylint==1.7.1
-pyparsing==2.2.0
-pytest-cov==2.5.1
-pytest-forked==0.2
-pytest-xdist==1.22.5
-pytest==3.7.1
-requests==2.19.1
-scandir==1.9.0
-selenium==3.14.0
-singledispatch==3.4.0.3
-six==1.11.0
+pylint==1.7.6
+pyparsing==2.3.1
+pytest-cov==2.6.1
+pytest-forked==1.0.2
+pytest-xdist==1.26.1
+pytest==4.2.1
+requests==2.21.0
+selenium==3.141.0
+six==1.12.0
+toml==0.10.0
 tox-battery==0.5.1
-tox-travis==0.10
-tox==3.2.1
-urllib3==1.23
-virtualenv==16.0.0
-wrapt==1.10.11
+tox-travis==0.11
+tox==3.7.0
+urllib3==1.24.1
+virtualenv==16.4.0
+wrapt==1.11.1
diff --git a/requirements/doc.in b/requirements/doc.in
index 71980bfd..fafbf859 100644
--- a/requirements/doc.in
+++ b/requirements/doc.in
@@ -1,5 +1,7 @@
 # Requirements for documentation generation
 
+-c constraints.txt
+
 -r base.txt               # Core bok-choy dependencies
 
 edx-sphinx-theme          # edX theme for Sphinx output
diff --git a/requirements/doc.txt b/requirements/doc.txt
index 59fea2e7..5aa4ba51 100644
--- a/requirements/doc.txt
+++ b/requirements/doc.txt
@@ -4,34 +4,28 @@
 #
 #    make upgrade
 #
-alabaster==0.7.11         # via sphinx
+alabaster==0.7.12         # via sphinx
 babel==2.6.0              # via sphinx
-bleach==2.1.3             # via readme-renderer
-certifi==2018.4.16        # via requests
-cffi==1.11.5              # via cmarkgfm
+bleach==3.1.0             # via readme-renderer
+certifi==2018.11.29       # via requests
 chardet==3.0.4            # via requests
-cmarkgfm==0.4.2           # via readme-renderer
 docutils==0.14            # via readme-renderer, sphinx
-edx-sphinx-theme==1.3.0
-future==0.16.0            # via readme-renderer
-html5lib==1.0.1           # via bleach
-idna==2.7                 # via requests
-imagesize==1.0.0          # via sphinx
+edx-sphinx-theme==1.4.0
+idna==2.8                 # via requests
+imagesize==1.1.0          # via sphinx
 jinja2==2.10              # via sphinx
-lazy==1.3
-markupsafe==1.0           # via jinja2
-packaging==17.1           # via sphinx
-pycparser==2.18           # via cffi
-pygments==2.2.0           # via readme-renderer, sphinx
-pyparsing==2.2.0          # via packaging
-pytz==2018.5              # via babel
-readme-renderer==21.0
-requests==2.19.1          # via sphinx
-selenium==3.14.0
-six==1.11.0
+lazy==1.4
+markupsafe==1.1.0         # via jinja2
+packaging==19.0           # via sphinx
+pygments==2.3.1           # via readme-renderer, sphinx
+pyparsing==2.3.1          # via packaging
+pytz==2018.9              # via babel
+readme-renderer==24.0
+requests==2.21.0          # via sphinx
+selenium==3.141.0
+six==1.12.0
 snowballstemmer==1.2.1    # via sphinx
-sphinx==1.7.6
+sphinx==1.8.4
 sphinxcontrib-websupport==1.1.0  # via sphinx
-typing==3.6.4             # via sphinx
-urllib3==1.23
-webencodings==0.5.1       # via html5lib
+urllib3==1.24.1
+webencodings==0.5.1       # via bleach
diff --git a/requirements/needle.in b/requirements/needle.in
index a31a95a4..3e442e51 100644
--- a/requirements/needle.in
+++ b/requirements/needle.in
@@ -1,5 +1,7 @@
 # Requirements for test runs with needle installed for visual diff support
 
+-c constraints.txt
+
 -r test.txt                         # Base testing dependencies
 
 needle                              # For test assertions involving screenshots and visual diffs
diff --git a/requirements/needle.txt b/requirements/needle.txt
index e9f3bc9f..ae15ffc3 100644
--- a/requirements/needle.txt
+++ b/requirements/needle.txt
@@ -5,46 +5,38 @@
 #    make upgrade
 #
 apipkg==1.5
-astroid==1.5.2
-atomicwrites==1.1.5
-attrs==18.1.0
-backports.functools-lru-cache==1.5
+astroid==1.5.3
+atomicwrites==1.3.0
+attrs==18.2.0
 click-log==0.1.8
-click==6.7
-configparser==3.5.0
-coverage==4.5.1
-edx-lint==0.5.5
-enum34==1.1.6
+click==7.0
+coverage==4.5.2
+edx-lint==1.1.0
 execnet==1.5.0
-funcsigs==1.0.2
-futures==3.2.0 ; python_version == "2.7"
 isort==4.3.4
 lazy-object-proxy==1.3.1
-lazy==1.3
+lazy==1.4
 mccabe==0.6.1
 mock==2.0.0
-more-itertools==4.3.0
+more-itertools==5.0.0
 needle==0.5.0
 nose==1.3.7               # via needle
-packaging==17.1
-pathlib2==2.3.2
-pbr==4.2.0
-pillow==5.2.0             # via needle
-pluggy==0.7.1
-py==1.5.4
-pycodestyle==2.4.0
+packaging==19.0
+pbr==5.1.2
+pillow==5.4.1             # via needle
+pluggy==0.8.1
+py==1.7.0
+pycodestyle==2.5.0
 pylint-celery==0.3
 pylint-django==0.7.2
 pylint-plugin-utils==0.3
-pylint==1.7.1
-pyparsing==2.2.0
-pytest-cov==2.5.1
-pytest-forked==0.2
-pytest-xdist==1.22.5
-pytest==3.7.1
-scandir==1.9.0
-selenium==3.14.0
-singledispatch==3.4.0.3
-six==1.11.0
-urllib3==1.23
-wrapt==1.10.11
+pylint==1.7.6
+pyparsing==2.3.1
+pytest-cov==2.6.1
+pytest-forked==1.0.2
+pytest-xdist==1.26.1
+pytest==4.2.1
+selenium==3.141.0
+six==1.12.0
+urllib3==1.24.1
+wrapt==1.11.1
diff --git a/requirements/pip-tools.in b/requirements/pip-tools.in
index c17d0b41..0295d2c8 100644
--- a/requirements/pip-tools.in
+++ b/requirements/pip-tools.in
@@ -1,3 +1,5 @@
 # Just the dependencies to run pip-tools, mainly for the "upgrade" make target
 
+-c constraints.txt
+
 pip-tools                 # Contains pip-compile, used to generate pip requirements files
diff --git a/requirements/pip-tools.txt b/requirements/pip-tools.txt
index e7027f3f..9de74284 100644
--- a/requirements/pip-tools.txt
+++ b/requirements/pip-tools.txt
@@ -4,7 +4,6 @@
 #
 #    make upgrade
 #
-click==6.7                # via pip-tools
-first==2.0.1              # via pip-tools
-pip-tools==2.0.2
-six==1.11.0               # via pip-tools
+click==7.0                # via pip-tools
+pip-tools==3.3.2
+six==1.12.0               # via pip-tools
diff --git a/requirements/test.in b/requirements/test.in
index 8eb59582..d3e640c8 100644
--- a/requirements/test.in
+++ b/requirements/test.in
@@ -1,5 +1,7 @@
 # Additional requirements for test runs.
 
+-c constraints.txt
+
 -r base.txt               # Core bok-choy dependencies
 
 edx_lint                            # pylint plug-ins for additional code quality checks
@@ -7,6 +9,5 @@ futures ; python_version == "2.7"   # via isort
 mock                                # For mocking functionality in assorted tests
 packaging                           # For version number parsing and comparisons
 pycodestyle                         # For checking compliance with PEP 8 coding style guidelines
-pylint-plugin-utils<0.4             # via pylint-celery, pylint-django; newer versions drop Python 2 support
 pytest-cov                          # For code coverage statistics generation
 pytest-xdist                        # For parallel test execution
diff --git a/requirements/test.txt b/requirements/test.txt
index 48e46c7f..810bc832 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -5,43 +5,35 @@
 #    make upgrade
 #
 apipkg==1.5               # via execnet
-astroid==1.5.2            # via edx-lint, pylint, pylint-celery
-atomicwrites==1.1.5       # via pytest
-attrs==18.1.0             # via pytest
-backports.functools-lru-cache==1.5  # via astroid, pylint
+astroid==1.5.3            # via edx-lint, pylint, pylint-celery
+atomicwrites==1.3.0       # via pytest
+attrs==18.2.0             # via pytest
 click-log==0.1.8          # via edx-lint
-click==6.7                # via click-log, edx-lint
-configparser==3.5.0       # via pylint
-coverage==4.5.1           # via pytest-cov
-edx-lint==0.5.5
-enum34==1.1.6             # via astroid
+click==7.0                # via click-log, edx-lint
+coverage==4.5.2           # via pytest-cov
+edx-lint==1.1.0
 execnet==1.5.0            # via pytest-xdist
-funcsigs==1.0.2           # via mock, pytest
-futures==3.2.0 ; python_version == "2.7"
 isort==4.3.4              # via pylint
 lazy-object-proxy==1.3.1  # via astroid
-lazy==1.3
+lazy==1.4
 mccabe==0.6.1             # via pylint
 mock==2.0.0
-more-itertools==4.3.0     # via pytest
-packaging==17.1
-pathlib2==2.3.2           # via pytest
-pbr==4.2.0                # via mock
-pluggy==0.7.1             # via pytest
-py==1.5.4                 # via pytest
-pycodestyle==2.4.0
+more-itertools==5.0.0     # via pytest
+packaging==19.0
+pbr==5.1.2                # via mock
+pluggy==0.8.1             # via pytest
+py==1.7.0                 # via pytest
+pycodestyle==2.5.0
 pylint-celery==0.3        # via edx-lint
 pylint-django==0.7.2      # via edx-lint
-pylint-plugin-utils==0.3
-pylint==1.7.1             # via edx-lint, pylint-celery, pylint-django, pylint-plugin-utils
-pyparsing==2.2.0          # via packaging
-pytest-cov==2.5.1
-pytest-forked==0.2        # via pytest-xdist
-pytest-xdist==1.22.5
-pytest==3.7.1             # via pytest-cov, pytest-forked, pytest-xdist
-scandir==1.9.0            # via pathlib2
-selenium==3.14.0
-singledispatch==3.4.0.3   # via astroid, pylint
-six==1.11.0
-urllib3==1.23
-wrapt==1.10.11            # via astroid
+pylint-plugin-utils==0.3  # via pylint-celery, pylint-django
+pylint==1.7.6             # via edx-lint, pylint-celery, pylint-django, pylint-plugin-utils
+pyparsing==2.3.1          # via packaging
+pytest-cov==2.6.1
+pytest-forked==1.0.2      # via pytest-xdist
+pytest-xdist==1.26.1
+pytest==4.2.1             # via pytest-cov, pytest-forked, pytest-xdist
+selenium==3.141.0
+six==1.12.0
+urllib3==1.24.1
+wrapt==1.11.1             # via astroid
diff --git a/requirements/travis.in b/requirements/travis.in
index f2337814..7ba64b41 100644
--- a/requirements/travis.in
+++ b/requirements/travis.in
@@ -1,6 +1,8 @@
 # Packages needed in order to run tox.
 # Installed by Travis and dev environments.
 
+-c constraints.txt
+
 codecov                   # Code coverage reporting
 tox                       # Virtualenv management for tests
 tox-battery               # Makes tox aware of requirements file changes
diff --git a/requirements/travis.txt b/requirements/travis.txt
index 4dc4ec6d..68f38243 100644
--- a/requirements/travis.txt
+++ b/requirements/travis.txt
@@ -4,17 +4,19 @@
 #
 #    make upgrade
 #
-certifi==2018.4.16        # via requests
+certifi==2018.11.29       # via requests
 chardet==3.0.4            # via requests
 codecov==2.0.15
-coverage==4.5.1           # via codecov
-idna==2.7                 # via requests
-pluggy==0.7.1             # via tox
-py==1.5.4                 # via tox
-requests==2.19.1          # via codecov
-six==1.11.0               # via tox
+coverage==4.5.2           # via codecov
+filelock==3.0.10          # via tox
+idna==2.8                 # via requests
+pluggy==0.8.1             # via tox
+py==1.7.0                 # via tox
+requests==2.21.0          # via codecov
+six==1.12.0               # via tox
+toml==0.10.0              # via tox
 tox-battery==0.5.1
-tox-travis==0.10
-tox==3.2.1
-urllib3==1.23             # via requests
-virtualenv==16.0.0        # via tox
+tox-travis==0.11
+tox==3.7.0
+urllib3==1.24.1           # via requests
+virtualenv==16.4.0        # via tox
diff --git a/setup.py b/setup.py
index 06277522..4693b695 100644
--- a/setup.py
+++ b/setup.py
@@ -6,7 +6,7 @@
 import sys
 from setuptools import setup
 
-VERSION = '0.9.2'
+VERSION = '0.9.3'
 DESCRIPTION = 'UI-level acceptance test framework'
 
 
@@ -31,6 +31,7 @@ def is_requirement(line):
     """
     return not (
         line == '' or
+        line.startswith('-c') or
         line.startswith('-r') or
         line.startswith('#') or
         line.startswith('-e') or
diff --git a/tests/pages.py b/tests/pages.py
index f44374e9..65a685f2 100644
--- a/tests/pages.py
+++ b/tests/pages.py
@@ -78,13 +78,13 @@ def select_car(self, car_value):
         """
         Select the car with ``car_value`` in the drop-down list.
         """
-        self.q(css='select[name="cars"] option[value="{}"]'.format(car_value)).first.click()
+        self.q(css=u'select[name="cars"] option[value="{}"]'.format(car_value)).first.click()
 
     def is_car_selected(self, car):
         """
         Return ``True`` if the given ``car`` is selected, ``False`` otherwise.
         """
-        return self.q(css='select[name="cars"] option[value="{}"]'.format(car)).selected
+        return self.q(css=u'select[name="cars"] option[value="{}"]'.format(car)).selected
 
 
 class CheckboxPage(SitePage):
@@ -97,7 +97,7 @@ def toggle_pill(self, pill_name):
         """
         Toggle the box for the pill with `pill_name` (red or blue).
         """
-        self.q(css="#fixture input#{}".format(pill_name)).first.click()
+        self.q(css=u"#fixture input#{}".format(pill_name)).first.click()
 
 
 class AlertPage(SitePage):
diff --git a/tests/test_browser.py b/tests/test_browser.py
index 855276b6..eb39a7d2 100644
--- a/tests/test_browser.py
+++ b/tests/test_browser.py
@@ -299,9 +299,9 @@ def test_save_driver_logs_exception(self, caplog):
         # Check that no files were created.
         log_types = browser.log_types
         for log_type in log_types:
-            expected_file = os.path.join(tempdir_path, 'js_page_{}.log'.format(log_type))
+            expected_file = os.path.join(tempdir_path, u'js_page_{}.log'.format(log_type))
             assert not os.path.exists(expected_file)
-            assert "Could not save browser log of type '{}'.".format(log_type) in caplog.text
+            assert u"Could not save browser log of type '{}'.".format(log_type) in caplog.text
 
     def test_save_source(self):
         browser = self.browser
diff --git a/tests/test_page_object.py b/tests/test_page_object.py
index e86e6bd4..1514247f 100644
--- a/tests/test_page_object.py
+++ b/tests/test_page_object.py
@@ -118,7 +118,7 @@ def test_validate_url(self):
             self.assertEqual(
                 returned_val,
                 is_valid,
-                msg="Url: {0}, Expected {1} but got {2}".format(url, is_valid, returned_val)
+                msg=u"Url: {0}, Expected {1} but got {2}".format(url, is_valid, returned_val)
             )
 
     def test_guarded_methods(self):