diff --git a/reviewboard/webapi/resources/filediff.py b/reviewboard/webapi/resources/filediff.py
index b2039891281a7f4e17b713c20f250543b1db0638..694f843b57e9d84423953b137e93f32cd94a9822 100644
--- a/reviewboard/webapi/resources/filediff.py
+++ b/reviewboard/webapi/resources/filediff.py
@@ -55,7 +55,7 @@ class FileDiffResource(WebAPIResource):
             'type': StringFieldType,
             'description': 'The encoding of the original and patched file, '
                            'if available.',
-            'added_in': '5.0.7',
+            'added_in': '5.0.8',
         },
         'extra_data': {
             'type': DictFieldType,