diff --git a/qubes/api/__init__.py b/qubes/api/__init__.py
index 38532913..f35974ec 100644
--- a/qubes/api/__init__.py
+++ b/qubes/api/__init__.py
@@ -323,7 +323,7 @@ class QubesDaemonProtocol(asyncio.Protocol):
         self.send_header(0x31)
 
         if subject is not self.app:
-            self.transport.write(subject.name.encode('ascii'))
+            self.transport.write(str(subject).encode('ascii'))
         self.transport.write(b'\0')
 
         self.transport.write(event.encode('ascii') + b'\0')
diff --git a/qubes/tests/api.py b/qubes/tests/api.py
index b24ab80e..ba74a208 100644
--- a/qubes/tests/api.py
+++ b/qubes/tests/api.py
@@ -77,7 +77,11 @@ class TestMgmt(object):
 
         class Subject:
             name = 'subject'
-        self.send_event(Subject, 'event', payload=untrusted_payload.decode())
+
+            def __str__(self):
+                return 'subject'
+
+        self.send_event(Subject(), 'event', payload=untrusted_payload.decode())
         try:
             # give some time to close the other end
             yield from asyncio.sleep(0.1)