diff --git a/presubmit_support.py b/presubmit_support.py
index e1fcd3d08..a292bd78d 100755
--- a/presubmit_support.py
+++ b/presubmit_support.py
@@ -186,15 +186,16 @@ class InputApi(object):
 
   # File extensions that are considered source files from a style guide
   # perspective. Don't modify this list from a presubmit script!
+  #
+  # Files without an extension aren't included in the list. If you want to
+  # filter them as source files, add r"(^|.*?[\\\/])[^.]+$" to the white list.
+  # Note that ALL CAPS files are black listed in DEFAULT_BLACK_LIST below.
   DEFAULT_WHITE_LIST = (
       # C++ and friends
       r".+\.c$", r".+\.cc$", r".+\.cpp$", r".+\.h$", r".+\.m$", r".+\.mm$",
       r".+\.inl$", r".+\.asm$", r".+\.hxx$", r".+\.hpp$", r".+\.s$", r".+\.S$",
       # Scripts
       r".+\.js$", r".+\.py$", r".+\.sh$", r".+\.rb$", r".+\.pl$", r".+\.pm$",
-      # No extension at all, note that ALL CAPS files are black listed in
-      # DEFAULT_BLACK_LIST below.
-      r"(^|.*?[\\\/])[^.]+$",
       # Other
       r".+\.java$", r".+\.mk$", r".+\.am$",
   )
diff --git a/tests/presubmit_unittest.py b/tests/presubmit_unittest.py
index 9ef2675b0..7f87be418 100755
--- a/tests/presubmit_unittest.py
+++ b/tests/presubmit_unittest.py
@@ -945,7 +945,6 @@ class InputApiUnittest(PresubmitTestsBase):
         ],
         [
           # Expected.
-          'a/experimental',
           'a/experimental.cc',
           'a/experimental.S',
         ],
@@ -960,7 +959,6 @@ class InputApiUnittest(PresubmitTestsBase):
         ],
         [
           # Expected.
-          'a/third_party',
           'a/third_party.cc',
         ],
       ),
@@ -970,11 +968,13 @@ class InputApiUnittest(PresubmitTestsBase):
           f('a/LOL_FILE/b'),
           f('b.c/LOL_FILE'),
           f('a/PRESUBMIT.py'),
+          f('a/FOO.json'),
+          f('a/FOO.java'),
         ],
         [
           # Expected.
-          'a/LOL_FILE/b',
           'a/PRESUBMIT.py',
+          'a/FOO.java',
         ],
       ),
       (
@@ -995,7 +995,7 @@ class InputApiUnittest(PresubmitTestsBase):
         False, None, False)
     self.mox.ReplayAll()
 
-    self.assertEqual(len(input_api.DEFAULT_WHITE_LIST), 22)
+    self.assertEqual(len(input_api.DEFAULT_WHITE_LIST), 21)
     self.assertEqual(len(input_api.DEFAULT_BLACK_LIST), 9)
     for item in files:
       results = filter(input_api.FilterSourceFile, item[0])