diff --git a/gen/generator-config.json b/gen/generator-config.json
index cfb1d9b..78ef2aa 100644
--- a/gen/generator-config.json
+++ b/gen/generator-config.json
@@ -3,5 +3,5 @@
   "packageName": "mux_python",
   "projectName": "mux_python",
   "licenseInfo" : "MIT",
-  "packageVersion": "5.1.0"
+  "packageVersion": "5.1.1"
 }
diff --git a/gen/templates/rest.mustache b/gen/templates/rest.mustache
index a172e98..0a8f0fd 100644
--- a/gen/templates/rest.mustache
+++ b/gen/templates/rest.mustache
@@ -35,7 +35,7 @@ class RESTResponse(io.IOBase):
 
     def getheader(self, name, default=None):
         """Returns a given response header."""
-        return self.urllib3_response.getheader(name, default)
+        return self.urllib3_response.headers.get(name, default)
 
 
 class RESTClientObject(object):
diff --git a/mux_python/__init__.py b/mux_python/__init__.py
index 3ecab10..8749eb2 100644
--- a/mux_python/__init__.py
+++ b/mux_python/__init__.py
@@ -15,7 +15,7 @@
 
 from __future__ import absolute_import
 
-__version__ = "5.1.0"
+__version__ = "5.1.1"
 
 # import apis into sdk package
 from mux_python.api.annotations_api import AnnotationsApi
diff --git a/mux_python/api_client.py b/mux_python/api_client.py
index 158ce54..b9c7069 100644
--- a/mux_python/api_client.py
+++ b/mux_python/api_client.py
@@ -79,7 +79,7 @@ def __init__(self, configuration=None, header_name=None, header_value=None,
             self.default_headers[header_name] = header_value
         self.cookie = cookie
         # Set default User-Agent.
-        self.user_agent = 'Mux Python | 5.1.0'
+        self.user_agent = 'Mux Python | 5.1.1'
         self.client_side_validation = configuration.client_side_validation
 
     def __enter__(self):
diff --git a/mux_python/configuration.py b/mux_python/configuration.py
index e21e31e..30b2c0d 100644
--- a/mux_python/configuration.py
+++ b/mux_python/configuration.py
@@ -406,7 +406,7 @@ def to_debug_report(self):
                "OS: {env}\n"\
                "Python Version: {pyversion}\n"\
                "Version of the API: v1\n"\
-               "SDK Package Version: 5.1.0".\
+               "SDK Package Version: 5.1.1".\
                format(env=sys.platform, pyversion=sys.version)
 
     def get_host_settings(self):
diff --git a/mux_python/rest.py b/mux_python/rest.py
index 8891e92..0529b15 100644
--- a/mux_python/rest.py
+++ b/mux_python/rest.py
@@ -44,7 +44,7 @@ def getheaders(self):
 
     def getheader(self, name, default=None):
         """Returns a given response header."""
-        return self.urllib3_response.getheader(name, default)
+        return self.urllib3_response.headers.get(name, default)
 
 
 class RESTClientObject(object):
diff --git a/setup.py b/setup.py
index 99c7348..764bb99 100644
--- a/setup.py
+++ b/setup.py
@@ -15,7 +15,7 @@
 from setuptools import setup, find_packages  # noqa: H301
 
 NAME = "mux_python"
-VERSION = "5.1.0"
+VERSION = "5.1.1"
 # To install the library, run the following
 #
 # python setup.py install