diff --git a/interfaces/python/Cantera/Reactor.py b/interfaces/python/Cantera/Reactor.py
index f7ad3f7ac..c72b331e0 100644
--- a/interfaces/python/Cantera/Reactor.py
+++ b/interfaces/python/Cantera/Reactor.py
@@ -943,7 +943,7 @@ class Wall:
         """
         if qfunc:
             self._qfunc = qfunc # hold on to a reference so it doesn't get deleted
-            n = self.qfunc.func_id()
+            n = qfunc.func_id()
         else:
             n = 0
         return _cantera.wall_setHeatFlux(self.__wall_id, n)