diff --git a/README.rst b/README.rst
index 98df2ba..877ccf6 100644
--- a/README.rst
+++ b/README.rst
@@ -42,3 +42,4 @@ namespace:
   package and put it into the metadata of every transaction.
 * `elasticapm.transactions_ignore_patterns`: Whitespace separated list of
   ignore patterns.
+* `elasticapm.transaction_sample_rate`: Transaction sample rate
diff --git a/requirements.lock b/requirements.lock
index 39e1dea..df2824c 100644
--- a/requirements.lock
+++ b/requirements.lock
@@ -23,7 +23,7 @@ py==1.10.0
 pycodestyle==2.7.0
 pyflakes==2.3.1
 pyparsing==2.4.7
-pyramid==2.0
+pyramid==1.8.0
 pytest-cache==1.0
 pytest-cov==2.11.1
 pytest-flake8==1.0.7
diff --git a/src/pyramid_elasticapm/__init__.py b/src/pyramid_elasticapm/__init__.py
index 9ed2e6a..55478e0 100644
--- a/src/pyramid_elasticapm/__init__.py
+++ b/src/pyramid_elasticapm/__init__.py
@@ -6,7 +6,7 @@
 import pkg_resources
 from elasticapm.utils import compat, get_url_dict
 from pyramid.events import ApplicationCreated, subscriber
-from pyramid.util import reraise
+from pyramid._compat import reraise
 
 
 def includeme(config):
@@ -37,6 +37,7 @@ def __init__(self, handler, registry):
             'SERVER_URL': settings['elasticapm.server_url'],
             'SECRET_TOKEN': settings['elasticapm.secret_token'],
             'ENVIRONMENT': settings['elasticapm.environment'],
+            'TRANSACTION_SAMPLE_RATE': settings['elasticapm.transaction_sample_rate'],
         }
         if settings.get('elasticapm.transactions_ignore_patterns', ''):
             config['TRANSACTIONS_IGNORE_PATTERNS'] = settings[
@@ -67,6 +68,8 @@ def __init__(self, handler, registry):
 
     def __call__(self, request):
         self.client.begin_transaction('request')
+        transaction_result = ""
+        response = None
         try:
             response = self.handler(request)
             transaction_result = response.status[0] + 'xx'
@@ -109,7 +112,7 @@ def get_data_from_request(self, request, response):
         # remove Cookie header since the same data is in
         # request["cookies"] as well
         data['headers'].pop('Cookie', None)
-        if response.status_code >= 400:
+        if response is not None and response.status_code >= 400:
             data['body'] = request.body
             data['response_body'] = response.body
         return data
@@ -121,7 +124,7 @@ def get_data_from_response(self, response):
         if response.headers:
             data['headers'] = {
                 key: ';'.join(response.headers.getall(key))
-                for key in compat.iterkeys(response.headers)
+                for key in response.headers.iterkeys()
             }
         return data
 
diff --git a/src/pyramid_elasticapm/tests/test_plugin.py b/src/pyramid_elasticapm/tests/test_plugin.py
index b5c1557..8c9cbbc 100644
--- a/src/pyramid_elasticapm/tests/test_plugin.py
+++ b/src/pyramid_elasticapm/tests/test_plugin.py
@@ -12,6 +12,7 @@ def make_app(server_url):
         'elasticapm.environment': 'testing',
         'elasticapm.service_distribution': 'pytest',
         'elasticapm.transactions_ignore_patterns': 'foo bar baz',
+        'elasticapm.transaction_sample_rate': 1.0,
     }
     config = Configurator(settings=settings)
     config.include('pyramid_elasticapm')