diff --git a/src/SuperBeam/RequestHandlers.py b/src/SuperBeam/RequestHandlers.py
index 7a8d346..33f2f42 100644
--- a/src/SuperBeam/RequestHandlers.py
+++ b/src/SuperBeam/RequestHandlers.py
@@ -33,7 +33,7 @@ class OctetStreamHandler(object):
     @staticmethod
     def handle(httpd):
         raise Exception(f'Not implemented: Unable to handle {httpd} '
-                        '({StreamHandler.mimetype}')
+                        '({OctetStreamHandler.mimetype}')
 
 
 class ChunkTemplateHandler(BaseTextHandler):