diff --git a/schemas/filetype.yaml b/schemas/filetype.yaml
index 6c89d83..38a7a9b 100644
--- a/schemas/filetype.yaml
+++ b/schemas/filetype.yaml
@@ -54,7 +54,7 @@ classes:
                     A list of any known file extensions that files of this `FileType`
                     are found with. These may be used as a hint for `FileType` detection.
                     Should omit the leading `'.'`, e.g. 'json' or 'txt'.
-                pattern: ^[A-z,0-9]*[A-z,0-9]+$
+                pattern: ^[A-z,0-9]*[A-z,0-9,.]+[A-z,0-9]$
             base_formats:
                 multivalued: true
                 range: FileType