diff --git a/CleanSpec.mk b/CleanSpec.mk
index 2e6bf1e..3e1f5be 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -111,6 +111,10 @@
 # Remove symbols/apex/com.android.art symlink (b/171406631)
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/symbols/apex/com.android.art)
 
+# art/tools/build_linux_bionic_tests.sh uses find here and can encounter
+# libdexfile_external.so in incremental builds.
+$(call add-clean-step, rm -rf $(HOST_OUT))
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************