diff --git a/pyglossary/plugins/aard2_slob/writer.py b/pyglossary/plugins/aard2_slob/writer.py
index 5ce9bc014..e6156bbfc 100644
--- a/pyglossary/plugins/aard2_slob/writer.py
+++ b/pyglossary/plugins/aard2_slob/writer.py
@@ -56,6 +56,8 @@ class Writer:
 		"otf": "application/x-font-opentype",
 		"mp3": "audio/mpeg",
 		"ogg": "audio/ogg",
+		"opus": "audio/ogg",
+		"oga": "audio/ogg",
 		"spx": "audio/x-speex",
 		"wav": "audio/wav",
 		"ini": "text/plain",