diff --git a/myhdl/test/conversion/general/test_interfaces3.py b/myhdl/test/conversion/general/test_interfaces3.py
index fd1fb80b..d9b49d53 100644
--- a/myhdl/test/conversion/general/test_interfaces3.py
+++ b/myhdl/test/conversion/general/test_interfaces3.py
@@ -140,6 +140,7 @@ def c_testbench_three():
     
     @instance
     def tbclk():
+        clock.next = False
         while True:
             yield delay(3)
             clock.next = not clock