diff --git a/Tests/images/itxt_chunks.png b/Tests/images/itxt_chunks.png
new file mode 100644
index 000000000..ca098440c
Binary files /dev/null and b/Tests/images/itxt_chunks.png differ
diff --git a/Tests/test_pickle.py b/Tests/test_pickle.py
index 46958c085..45ef0f1db 100644
--- a/Tests/test_pickle.py
+++ b/Tests/test_pickle.py
@@ -67,9 +67,13 @@ class TestPickle(PillowTestCase):
                 "Tests/images/non_zero_bb.png",
                 "Tests/images/non_zero_bb_scale2.png",
                 "Tests/images/p_trns_single.png",
-                "Tests/images/pil123p.png"
+                "Tests/images/pil123p.png",
+                "Tests/images/itxt_chunks.png"
         ]:
-            self.helper_pickle_string(pickle, test_file=test_file)
+            for protocol in range(0, pickle.HIGHEST_PROTOCOL + 1):
+                self.helper_pickle_string(pickle,
+                                          protocol=protocol,
+                                          test_file=test_file)
 
     def test_pickle_l_mode(self):
         # Arrange
diff --git a/src/PIL/PngImagePlugin.py b/src/PIL/PngImagePlugin.py
index 4b8b10a51..e04ae2274 100644
--- a/src/PIL/PngImagePlugin.py
+++ b/src/PIL/PngImagePlugin.py
@@ -194,7 +194,7 @@ class iTXt(str):
 
     """
     @staticmethod
-    def __new__(cls, text, lang, tkey):
+    def __new__(cls, text, lang=None, tkey=None):
         """
         :param cls: the class to use when creating the instance
         :param text: value for this key