diff --git a/test/test_utils.py b/test/test_utils.py
index e7d4e03309..a3a23fbb4a 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -56,7 +56,7 @@ class TestUtil(unittest.TestCase):
 		self.assertEqual(sanitize_filename(u'aäb中国的c', restricted=True), u'a_b_c')
 		self.assertTrue(sanitize_filename(u'ö', restricted=True) != u'') # No empty filename
 
-		forbidden = u'"\0\\/&: \'\t\n'
+		forbidden = u'"\0\\/&!: \'\t\n'
 		for fc in forbidden:
 			for fbc in forbidden:
 				self.assertTrue(fbc not in sanitize_filename(fc, restricted=True))
diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index 4ace22c2fc..a0c41081ac 100644
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -208,7 +208,7 @@ def sanitize_filename(s, restricted=False):
 			return '_-' if restricted else ' -'
 		elif char in '\\/|*<>':
 			return '_'
-		if restricted and (char in '&\'' or char.isspace()):
+		if restricted and (char in '!&\'' or char.isspace()):
 			return '_'
 		if restricted and ord(char) > 127:
 			return '_'
@@ -316,7 +316,7 @@ class ContentTooShortError(Exception):
 
 class Trouble(Exception):
 	"""Trouble helper exception
-	
+
 	This is an exception to be handled with
 	FileDownloader.trouble
 	"""