diff --git a/smalltag/smalltag.py b/smalltag/smalltag.py
index a2eebbd..2093d06 100644
--- a/smalltag/smalltag.py
+++ b/smalltag/smalltag.py
@@ -15,13 +15,13 @@ UnsupportedFormatError = tinytag.UnsupportedFormatError
 class SmallTag(TinyTag):
     _file_extension_mapping: dict[tuple[str, ...], type[SmallTag]]= {
         (".mp1", ".mp2", ".mp3"): None,
-        ('.oga', '.ogg', '.opus', '.spx'): None,
-        ('.wav',): tinytag._Wave,
-        ('.flac',): tinytag._Flac,
-        ('.wma',): tinytag._Wma,
-        ('.m4b', '.m4a', '.m4r', '.m4v', '.mp4',
-         '.aax', '.aaxc'): tinytag._MP4,
-        ('.aiff', '.aifc', '.aif', '.afc'): tinytag._Aiff,
+        (".oga", ".ogg", ".opus", ".spx"): None,
+        (".wav",): tinytag._Wave,
+        (".flac",): tinytag._Flac,
+        (".wma",): tinytag._Wma,
+        (".m4b", ".m4a", ".m4r", ".m4v", ".mp4",
+         ".aax", ".aaxc"): tinytag._MP4,
+        (".aiff", ".aifc", ".aif", ".afc"): tinytag._Aiff,
     }
 
     @classmethod