diff --git a/src/betterproto/templates/template.py.j2 b/src/betterproto/templates/template.py.j2
index 61c18632b..c80cd7748 100644
--- a/src/betterproto/templates/template.py.j2
+++ b/src/betterproto/templates/template.py.j2
@@ -179,6 +179,9 @@ class {{ service.py_name }}Base(ServiceBase):
 
         {% endif %}
         raise grpclib.GRPCError(grpclib.const.Status.UNIMPLEMENTED)
+        {% if method.server_streaming %}
+        yield {{ method.py_output_message_type }}()
+        {% endif %}
 
     {% endfor %}