diff --git a/python2/raygun4py/http_utilities.py b/python2/raygun4py/http_utilities.py
index bd29a4a..9e5f8ad 100644
--- a/python2/raygun4py/http_utilities.py
+++ b/python2/raygun4py/http_utilities.py
@@ -22,9 +22,9 @@ def build_wsgi_compliant_request(request):
         # fallback to wsgi.input
         if http_form is None and 'wsgi.input' in request:
             # we can assume WSGI keys inside this block
-            content_length = int(request.get('CONTENT_LENGTH', 0))
-            if content_length:
-                http_form = request['wsgi.input'].read(content_length)
+            content_length = request.get('CONTENT_LENGTH', 0)
+            if content_length and content_length != '':
+                http_form = request['wsgi.input'].read(int(content_length))
 
         rg_request = {
             'httpMethod': (request.get('httpMethod') or request.get('REQUEST_METHOD')),
@@ -43,10 +43,12 @@ def build_wsgi_compliant_request(request):
     _headers = request.get('headers')
     if _headers is None:
         # manually try to build up headers given known WSGI keys
-        _headers = {
-            'Content-Type': request.get('CONTENT_TYPE'),
-            'Content-Length': request.get('CONTENT_LENGTH'),
-        }
+        _headers = {}
+        # don't add content headers if they are empty strings, Werkzeug has strange defaults
+        if request.get('CONTENT_TYPE') != '':
+            _headers['Content-Type'] = request.get('CONTENT_TYPE')
+        if request.get('CONTENT_LENGTH') != '':
+            _headers['Content-Length'] = request.get('CONTENT_LENGTH')
 
         for key, value in request.items():
             if key.startswith('HTTP_'):
diff --git a/python2/raygun4py/middleware/flask.py b/python2/raygun4py/middleware/flask.py
index 36f19fb..676278e 100644
--- a/python2/raygun4py/middleware/flask.py
+++ b/python2/raygun4py/middleware/flask.py
@@ -11,9 +11,10 @@
 
 
 class Provider(object):
-    def __init__(self, flaskApp, apiKey):
+    def __init__(self, flaskApp, apiKey, config=None):
         self.flaskApp = flaskApp
         self.apiKey = apiKey
+        self.config = config
         self.sender = None
 
         got_request_exception.connect(self.send_exception, sender=flaskApp)
@@ -24,7 +25,7 @@ def attach(self):
         if not hasattr(self.flaskApp, 'extensions'):
             self.flaskApp.extensions = {}
 
-        self.sender = raygunprovider.RaygunSender(self.apiKey)
+        self.sender = raygunprovider.RaygunSender(self.apiKey, config=self.config)
         return self.sender
 
     def send_exception(self, *args, **kwargs):
diff --git a/python2/raygun4py/middleware/wsgi.py b/python2/raygun4py/middleware/wsgi.py
index 6fd201d..61ddee7 100644
--- a/python2/raygun4py/middleware/wsgi.py
+++ b/python2/raygun4py/middleware/wsgi.py
@@ -8,9 +8,9 @@
 
 class Provider(object):
 
-    def __init__(self, app, apiKey):
+    def __init__(self, app, apiKey, config=None):
         self.app = app
-        self.sender = raygunprovider.RaygunSender(apiKey)
+        self.sender = raygunprovider.RaygunSender(apiKey, config=config)
 
     def __call__(self, environ, start_response):
         if not self.sender:
diff --git a/python3/raygun4py/http_utilities.py b/python3/raygun4py/http_utilities.py
index bd29a4a..9e5f8ad 100644
--- a/python3/raygun4py/http_utilities.py
+++ b/python3/raygun4py/http_utilities.py
@@ -22,9 +22,9 @@ def build_wsgi_compliant_request(request):
         # fallback to wsgi.input
         if http_form is None and 'wsgi.input' in request:
             # we can assume WSGI keys inside this block
-            content_length = int(request.get('CONTENT_LENGTH', 0))
-            if content_length:
-                http_form = request['wsgi.input'].read(content_length)
+            content_length = request.get('CONTENT_LENGTH', 0)
+            if content_length and content_length != '':
+                http_form = request['wsgi.input'].read(int(content_length))
 
         rg_request = {
             'httpMethod': (request.get('httpMethod') or request.get('REQUEST_METHOD')),
@@ -43,10 +43,12 @@ def build_wsgi_compliant_request(request):
     _headers = request.get('headers')
     if _headers is None:
         # manually try to build up headers given known WSGI keys
-        _headers = {
-            'Content-Type': request.get('CONTENT_TYPE'),
-            'Content-Length': request.get('CONTENT_LENGTH'),
-        }
+        _headers = {}
+        # don't add content headers if they are empty strings, Werkzeug has strange defaults
+        if request.get('CONTENT_TYPE') != '':
+            _headers['Content-Type'] = request.get('CONTENT_TYPE')
+        if request.get('CONTENT_LENGTH') != '':
+            _headers['Content-Length'] = request.get('CONTENT_LENGTH')
 
         for key, value in request.items():
             if key.startswith('HTTP_'):
diff --git a/python3/raygun4py/middleware/flask.py b/python3/raygun4py/middleware/flask.py
index 11fdae4..f859829 100644
--- a/python3/raygun4py/middleware/flask.py
+++ b/python3/raygun4py/middleware/flask.py
@@ -7,9 +7,10 @@
 
 
 class Provider(object):
-    def __init__(self, flaskApp, apiKey):
+    def __init__(self, flaskApp, apiKey, config=None):
         self.flaskApp = flaskApp
         self.apiKey = apiKey
+        self.config = config
         self.sender = None
 
         got_request_exception.connect(self.send_exception, sender=flaskApp)
@@ -20,7 +21,7 @@ def attach(self):
         if not hasattr(self.flaskApp, 'extensions'):
             self.flaskApp.extensions = {}
 
-        self.sender = raygunprovider.RaygunSender(self.apiKey)
+        self.sender = raygunprovider.RaygunSender(self.apiKey, config=self.config)
         return self.sender
 
     def send_exception(self, *args, **kwargs):
diff --git a/python3/raygun4py/middleware/wsgi.py b/python3/raygun4py/middleware/wsgi.py
index 6fd201d..61ddee7 100644
--- a/python3/raygun4py/middleware/wsgi.py
+++ b/python3/raygun4py/middleware/wsgi.py
@@ -8,9 +8,9 @@
 
 class Provider(object):
 
-    def __init__(self, app, apiKey):
+    def __init__(self, app, apiKey, config=None):
         self.app = app
-        self.sender = raygunprovider.RaygunSender(apiKey)
+        self.sender = raygunprovider.RaygunSender(apiKey, config=config)
 
     def __call__(self, environ, start_response):
         if not self.sender: