diff --git a/requests/auth.py b/requests/auth.py
index 701104d0..d0d5829d 100644
--- a/requests/auth.py
+++ b/requests/auth.py
@@ -12,7 +12,6 @@ import re
 import time
 import hashlib
 import threading
-import warnings
 
 from base64 import b64encode
 
@@ -29,33 +28,13 @@ CONTENT_TYPE_MULTI_PART = 'multipart/form-data'
 def _basic_auth_str(username, password):
     """Returns a Basic Auth string."""
 
-    # "I want us to put a big-ol' comment on top of it that
-    # says that this behaviour is dumb but we need to preserve
-    # it because people are relying on it."
-    #    - Lukasa
-    #
-    # These are here solely to maintain backwards compatibility
-    # for things like ints. This will be removed in 3.0.0.
     if not isinstance(username, basestring):
-        warnings.warn(
-            "Non-string usernames will no longer be supported in Requests "
-            "3.0.0. Please convert the object you've passed in ({!r}) to "
-            "a string or bytes object in the near future to avoid "
-            "problems.".format(username),
-            category=DeprecationWarning,
-        )
-        username = str(username)
+        raise TypeError('username must be of type str or bytes, '
+                        'instead it was %s' % type(username))
 
     if not isinstance(password, basestring):
-        warnings.warn(
-            "Non-string passwords will no longer be supported in Requests "
-            "3.0.0. Please convert the object you've passed in ({!r}) to "
-            "a string or bytes object in the near future to avoid "
-            "problems.".format(password),
-            category=DeprecationWarning,
-        )
-        password = str(password)
-    # -- End Removal --
+        raise TypeError('password must be of type str or bytes, '
+                        'instead it was %s' % type(password))
 
     if isinstance(username, str):
         username = username.encode('latin1')
diff --git a/tests/test_requests.py b/tests/test_requests.py
index 70564d26..fdb0fa6a 100755
--- a/tests/test_requests.py
+++ b/tests/test_requests.py
@@ -514,8 +514,6 @@ class TestRequests:
         'username, password', (
             ('user', 'pass'),
             (u'имя'.encode('utf-8'), u'пароль'.encode('utf-8')),
-            (42, 42),
-            (None, None),
         ))
     def test_set_basicauth(self, httpbin, username, password):
         auth = (username, password)
@@ -526,6 +524,18 @@ class TestRequests:
 
         assert p.headers['Authorization'] == _basic_auth_str(username, password)
 
+    @pytest.mark.parametrize(
+        'username, password', (
+            ('user', 1234),
+            (None, 'test'),
+        ))
+    def test_non_str_basicauth(self, username, password):
+        """Ensure we only allow string or bytes values for basicauth"""
+        with pytest.raises(TypeError) as e:
+            requests.auth._basic_auth_str(username, password)
+
+        assert 'must be of type str or bytes' in str(e)
+
     def test_basicauth_encodes_byte_strings(self):
         """Ensure b'test' formats as the byte string "test" rather
         than the unicode string "b'test'" in Python 3.