diff --git a/sprockets/mixins/mediatype/content.py b/sprockets/mixins/mediatype/content.py
index bdc8bc6..7675b7e 100644
--- a/sprockets/mixins/mediatype/content.py
+++ b/sprockets/mixins/mediatype/content.py
@@ -148,9 +148,15 @@ def add_text_content_type(application, content_type, default_encoding,
     :param loads: function that loads a dictionary from a string.
         ``loads(str, encoding:str) -> dict``
 
+    Note that the ``charset`` parameter is stripped from `content_type`
+    if it is present.
+
     """
-    add_transcoder(application, content_type,
-                   handlers.TextContentHandler(content_type, dumps, loads,
+    parsed = headers.parse_content_type(content_type)
+    parsed.parameters.pop('charset', None)
+    normalized = str(parsed)
+    add_transcoder(application, normalized,
+                   handlers.TextContentHandler(normalized, dumps, loads,
                                                default_encoding))
 
 
diff --git a/tests.py b/tests.py
index ebd9546..9464209 100644
--- a/tests.py
+++ b/tests.py
@@ -240,6 +240,14 @@ class ContentFunctionTests(unittest.TestCase):
         self.assertIs(transcoder._dumps, json.dumps)
         self.assertIs(transcoder._loads, json.loads)
 
+    def test_that_add_text_content_type_discards_charset_parameter(self):
+        content.add_text_content_type(self.context,
+                                      'application/json;charset=UTF-8', 'utf8',
+                                      json.dumps, json.loads)
+        settings = content.ContentSettings.from_application(self.context)
+        transcoder = settings['application/json']
+        self.assertIsInstance(transcoder, handlers.TextContentHandler)
+
 
 class MsgPackTranscoderTests(unittest.TestCase):