diff --git a/PIL/_util.py b/PIL/_util.py
index eb5c2c242..51c6f6887 100644
--- a/PIL/_util.py
+++ b/PIL/_util.py
@@ -3,20 +3,25 @@ import os
 if bytes is str:
     def isStringType(t):
         return isinstance(t, basestring)
+
     def isPath(f):
         return isinstance(f, basestring)
 else:
     def isStringType(t):
         return isinstance(t, str)
+
     def isPath(f):
         return isinstance(f, (bytes, str))
 
+
 # Checks if an object is a string, and that it points to a directory.
 def isDirectory(f):
     return isPath(f) and os.path.isdir(f)
 
+
 class deferred_error(object):
     def __init__(self, ex):
         self.ex = ex
+
     def __getattr__(self, elt):
         raise self.ex
diff --git a/Tests/test_util.py b/Tests/test_util.py
new file mode 100644
index 000000000..a547c6bd6
--- /dev/null
+++ b/Tests/test_util.py
@@ -0,0 +1,81 @@
+from helper import unittest, PillowTestCase
+
+from PIL import _util
+
+
+class TestUtil(PillowTestCase):
+
+    def test_is_string_type(self):
+        # Arrange
+        color = "red"
+
+        # Act
+        it_is = _util.isStringType(color)
+
+        # Assert
+        self.assertTrue(it_is)
+
+    def test_is_not_string_type(self):
+        # Arrange
+        color = (255, 0, 0)
+
+        # Act
+        it_is_not = _util.isStringType(color)
+
+        # Assert
+        self.assertFalse(it_is_not)
+
+    def test_is_path(self):
+        # Arrange
+        fp = "filename.ext"
+
+        # Act
+        it_is = _util.isStringType(fp)
+
+        # Assert
+        self.assertTrue(it_is)
+
+    def test_is_not_path(self):
+        # Arrange
+        filename = self.tempfile("temp.ext")
+        fp = open(filename, 'w').close()
+
+        # Act
+        it_is_not = _util.isPath(fp)
+
+        # Assert
+        self.assertFalse(it_is_not)
+
+    def test_is_directory(self):
+        # Arrange
+        directory = "Tests"
+
+        # Act
+        it_is = _util.isDirectory(directory)
+
+        # Assert
+        self.assertTrue(it_is)
+
+    def test_is_not_directory(self):
+        # Arrange
+        text = "abc"
+
+        # Act
+        it_is_not = _util.isDirectory(text)
+
+        # Assert
+        self.assertFalse(it_is_not)
+
+    def test_deferred_error(self):
+        # Arrange
+
+        # Act
+        thing = _util.deferred_error(ValueError("Some error text"))
+
+        # Assert
+        self.assertRaises(ValueError, lambda: thing.some_attr)
+
+if __name__ == '__main__':
+    unittest.main()
+
+# End of file