diff --git a/CleanSpec.mk b/CleanSpec.mk
index 3430346e7c..bdd16d5f54 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -680,6 +680,8 @@ $(call add-clean-step, rm -rf $(SOONG_OUT_DIR)/host/*/fuzz/*)
 # Change file layout of system_other
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system_other)
 
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/apex)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************
diff --git a/target/board/mainline_arm64/BoardConfig.mk b/target/board/mainline_arm64/BoardConfig.mk
index 70505f4e12..ea2b3c5d76 100644
--- a/target/board/mainline_arm64/BoardConfig.mk
+++ b/target/board/mainline_arm64/BoardConfig.mk
@@ -34,3 +34,8 @@ AB_OTA_PARTITIONS := system
 
 BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE := ext4
 BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE := ext4
+
+# Mainline devices support apex
+# TODO: move this to BoardConfigMainlineCommon. Currently, GSI wants flattened
+#       apexes, but emulator wants .apex files, preventing this.
+TARGET_FLATTEN_APEX := false