diff --git a/scour/scour.py b/scour/scour.py
index ec5e5f8..8ab6c81 100644
--- a/scour/scour.py
+++ b/scour/scour.py
@@ -2866,8 +2866,9 @@ def serializeXML(element, options, ind = 0, preserveWhitespace = False):
 # input is a string representation of the input XML
 # returns a string representation of the output XML
 def scourString(in_string, options=None):
-   if options is None:
-      options = _options_parser.get_default_values()
+   # sanitize options (take missing attributes from defaults, discard unknown attributes)
+   options = sanitizeOptions(options)
+
    getcontext().prec = options.digits
    global numAttrsRemoved
    global numStylePropsFixed
@@ -3289,6 +3290,18 @@ def generateDefaultOptions():
    return Struct(**d)
 
 
+
+# sanitizes options by updating attributes in a set of defaults options while discarding unknown attributes
+def sanitizeOptions(options):
+   optionsDict = dict((key, getattr(options, key)) for key in dir(options) if not key.startswith('__'))
+
+   sanitizedOptions = _options_parser.get_default_values()
+   sanitizedOptions._update_careful(optionsDict)
+
+   return sanitizedOptions
+
+
+
 def start(options, input, output):
 
    start = walltime()
diff --git a/testscour.py b/testscour.py
index a5c8185..9697cfe 100755
--- a/testscour.py
+++ b/testscour.py
@@ -45,30 +45,31 @@ def walkTree(elem, func):
 		if walkTree(child, func) == False: return False
 	return True
 
+
 class ScourOptions:
-	simple_colors = True
-	style_to_xml = True
-	group_collapse = True
-	group_create = False
-	strip_ids = False
-	strip_comments = False
-	shorten_ids = False
-	shorten_ids_prefix = ""
-	embed_rasters = True
-	keep_defs = False
-	keep_editor_data = False
-	remove_metadata = False
-	renderer_workaround = True
-	strip_xml_prolog = False
-	enable_viewboxing = False
-	digits = 5
-	indent_type = "space"
-	indent_depth = 1
-	newlines = True
-	strip_xml_space_attribute = False
-	protect_ids_noninkscape = False
-	protect_ids_list = None
-	protect_ids_prefix = None
+	pass
+
+
+class EmptyOptions(unittest.TestCase):
+	def runTest(self):
+		options = ScourOptions
+		try:
+			scour.scourXmlFile('unittests/ids-to-strip.svg', options)
+			fail = False
+		except:
+			fail = True
+		self.assertEqual(fail, False, 'Exception when calling Scour with empty options object')
+
+class InvalidOptions(unittest.TestCase):
+	def runTest(self):
+		options = ScourOptions
+		options.invalidOption = "invalid value"
+		try:
+			scour.scourXmlFile('unittests/ids-to-strip.svg', options)
+			fail = False
+		except:
+			fail = True
+		self.assertEqual(fail, False, 'Exception when calling Scour with invalid options')
 
 class NoInkscapeElements(unittest.TestCase):
 	def runTest(self):