diff --git a/bitbake/lib/bb/cooker.py b/bitbake/lib/bb/cooker.py
index 054dac8634..8c55e3e643 100644
--- a/bitbake/lib/bb/cooker.py
+++ b/bitbake/lib/bb/cooker.py
@@ -734,7 +734,7 @@ class BBCooker:
             if not retval:
                 bb.event.fire(bb.event.BuildCompleted(buildname, targets, failures), self.configuration.event_data)
                 self.command.finishAsyncCommand()
-                return None
+                return False
             if retval is True:
                 return True
             return 0.5