diff --git a/ui/build/cleanbuild.go b/ui/build/cleanbuild.go
index bfe2c36..0a2b510 100644
--- a/ui/build/cleanbuild.go
+++ b/ui/build/cleanbuild.go
@@ -87,6 +87,7 @@
 	// otherwise we'd have to rebuild any generated files created with
 	// those tools.
 	removeGlobs(ctx,
+		hostOut("apex"),
 		hostOut("obj/NOTICE_FILES"),
 		hostOut("obj/PACKAGING"),
 		hostOut("coverage"),