diff --git a/reviewboard/webapi/resources/filediff.py b/reviewboard/webapi/resources/filediff.py
index e93214d5ee3576f46deb3907c3cd9a07e2815cbf..437dcf38ff96cb5c67c78499ecb3e7924b65b4cf 100644
--- a/reviewboard/webapi/resources/filediff.py
+++ b/reviewboard/webapi/resources/filediff.py
@@ -51,6 +51,12 @@ class FileDiffResource(WebAPIResource):
             'description': 'Whether this represents a binary file.',
             'added_in': '4.0.6',
         },
+        'encoding': {
+            'type': StringFieldType,
+            'description': 'The encoding of the original and patched file, '
+                           'if available.',
+            'added_in': '5.0.7',
+        },
         'extra_data': {
             'type': DictFieldType,
             'description': 'Extra data as part of the diff. '
diff --git a/reviewboard/webapi/tests/test_filediff.py b/reviewboard/webapi/tests/test_filediff.py
index 0cd6a4384289680efcc73df62df26a3123145222..150e532362763f730c349a013b1821d62045ea09 100644
--- a/reviewboard/webapi/tests/test_filediff.py
+++ b/reviewboard/webapi/tests/test_filediff.py
@@ -20,6 +20,7 @@ def _compare_item(self, item_rsp, filediff):
     self.assertEqual(item_rsp['id'], filediff.pk)
     self.assertEqual(item_rsp['binary'], filediff.binary)
     self.assertEqual(item_rsp['extra_data'], filediff.extra_data)
+    self.assertEqual(item_rsp['encoding'], filediff.encoding)
     self.assertEqual(item_rsp['source_file'], filediff.source_file)
     self.assertEqual(item_rsp['dest_file'], filediff.dest_file)
     self.assertEqual(item_rsp['source_revision'], filediff.source_revision)