diff --git a/presubmit_support.py b/presubmit_support.py
index ff57c9049..0da80ff77 100755
--- a/presubmit_support.py
+++ b/presubmit_support.py
@@ -507,7 +507,8 @@ class InputApi(object):
       # Scripts
       r".+\.js$", r".+\.py$", r".+\.sh$", r".+\.rb$", r".+\.pl$", r".+\.pm$",
       # Other
-      r".+\.java$", r".+\.mk$", r".+\.am$", r".+\.css$"
+      r".+\.java$", r".+\.mk$", r".+\.am$", r".+\.css$", r".+\.mojom$",
+      r".+\.fidl$"
   )
 
   # Path regexp that should be excluded from being considered containing source
diff --git a/tests/presubmit_unittest.py b/tests/presubmit_unittest.py
index 33b3e88aa..18402b0e3 100755
--- a/tests/presubmit_unittest.py
+++ b/tests/presubmit_unittest.py
@@ -1159,11 +1159,13 @@ class InputApiUnittest(PresubmitTestsBase):
           f('a/PRESUBMIT.py'),
           f('a/FOO.json'),
           f('a/FOO.java'),
+          f('a/FOO.mojom'),
         ],
         [
           # Expected.
           'a/PRESUBMIT.py',
           'a/FOO.java',
+          'a/FOO.mojom',
         ],
       ),
       (
@@ -1185,7 +1187,7 @@ class InputApiUnittest(PresubmitTestsBase):
         self.fake_change, './PRESUBMIT.py', False, None, False)
     self.mox.ReplayAll()
 
-    self.assertEqual(len(input_api.DEFAULT_WHITE_LIST), 22)
+    self.assertEqual(len(input_api.DEFAULT_WHITE_LIST), 24)
     self.assertEqual(len(input_api.DEFAULT_BLACK_LIST), 12)
     for item in files:
       results = filter(input_api.FilterSourceFile, item[0])