diff --git a/test/lib/xmpp_mocks.py b/test/lib/xmpp_mocks.py
index 4b6b469ad33be9cd549933a8f6175ab5f2c3e530..015d3ee31fdf3dc07130bbc6e307925877105237 100644
--- a/test/lib/xmpp_mocks.py
+++ b/test/lib/xmpp_mocks.py
@@ -47,7 +47,7 @@ class IdleMock:
 		Returns True if event was set, False on timeout
 		'''
 		self._event.wait(IDLEMOCK_TIMEOUT)
-		if self._event.is_set():
+		if self._event.isSet():
 			self._event.clear()
 			return True
 		else: