diff --git a/extensions/composer/extension.py b/extensions/composer/extension.py
index d3495253a..17c60db8d 100644
--- a/extensions/composer/extension.py
+++ b/extensions/composer/extension.py
@@ -94,7 +94,7 @@ def read_exts_from_path(self, path):
     def pick_php_version(self, requested):
         selected = None
 
-        if requested is None or requested is '':
+        if requested is None or requested == '':
             return self._ctx['PHP_VERSION']
 
         # requested is coming from the composer.json file and is a unicode string type.
diff --git a/extensions/dynatrace/extension.py b/extensions/dynatrace/extension.py
index 9f06df34c..2ae465470 100644
--- a/extensions/dynatrace/extension.py
+++ b/extensions/dynatrace/extension.py
@@ -260,7 +260,7 @@ def update_agent_config(self):
 
         # store static config in same kind of data structure (nested dictionary)
         # as we use for the config from we fetched from the API
-        section_regex = re.compile('\[(.*)\]')
+        section_regex = re.compile(r'\[(.*)\]')
         config_section = ""
         config_from_agent = dict()
         _log.debug("Starting to parse OneAgent config...")
diff --git a/extensions/sessions/extension.py b/extensions/sessions/extension.py
index 1e6820ab3..c489f98f1 100644
--- a/extensions/sessions/extension.py
+++ b/extensions/sessions/extension.py
@@ -111,13 +111,13 @@ def _compile(self, install):
         # modify php.ini to contain the right session config
         self.load_config()
         self._php_ini.update_lines(
-            '^session\.name = JSESSIONID$',
+            r'^session\.name = JSESSIONID$',
             'session.name = PHPSESSIONID')
         self._php_ini.update_lines(
-            '^session\.save_handler = files$',
+            r'^session\.save_handler = files$',
             'session.save_handler = %s' % self.service.EXTENSION_NAME)
         self._php_ini.update_lines(
-            '^session\.save_path = "@{TMPDIR}"$',
+            r'^session\.save_path = "@{TMPDIR}"$',
             'session.save_path = "%s"' % self.service.session_save_path())
         self.service.custom_config_php_ini(self._php_ini)
         self._php_ini.save(self._php_ini_path)
diff --git a/tests/test_composer.py b/tests/test_composer.py
index 63ce58eb4..1d050b60d 100644
--- a/tests/test_composer.py
+++ b/tests/test_composer.py
@@ -74,7 +74,7 @@ def test_composer_tool_install(self):
         installer.package.return_value.done.assert_called_once()
         # make sure composer is installed
         installer._installer._install_binary_from_manifest.assert_called_once()
-        assert re.match('/composer/[\d\.]+/composer.phar', installer._installer._install_binary_from_manifest.call_args[0][0]), \
+        assert re.match(r'/composer/[\d\.]+/composer.phar', installer._installer._install_binary_from_manifest.call_args[0][0]), \
             "was %s" % installer._installer._install_binary_from_manifest.call_args[0][0]
 
     def test_composer_tool_install_latest(self):