diff --git a/Makefile.cache b/Makefile.cache
index 69ab32a917b5..f5bf5ee86705 100644
--- a/Makefile.cache
+++ b/Makefile.cache
@@ -359,8 +359,10 @@ endef
 
 RFS_DEP_FILES := $(wildcard \
 	$(addprefix scripts/, build_debian_base_system.sh prepare_debian_image_buildinfo.sh build_mirror_config.sh) \
-	$(wildcard files/initramfs-tools/*) \
+	$(shell git ls-files files/initramfs-tools) \
 	$(shell git ls-files files/image_config) \
+	$(shell git ls-files files/apparmor) \
+	$(shell git ls-files files/apt) \
 	$(wildcard files/sshd/*) \
 	$(wildcard files/dhcp/*) \
 	src/sonic-build-hooks/buildinfo/trusted.gpg.d \
diff --git a/build_debian.sh b/build_debian.sh
index 6b93c09e023d..a6d563ba1259 100755
--- a/build_debian.sh
+++ b/build_debian.sh
@@ -612,8 +612,7 @@ if [[ $RFS_SPLIT_FIRST_STAGE == y ]]; then
     ## Kill the processes
     sudo LANG=C chroot $FILESYSTEM_ROOT fuser -km /proc || true
     ## Wait fuser fully kill the processes
-    sleep 15
-    sudo LANG=C chroot $FILESYSTEM_ROOT umount /proc
+    sudo timeout 15s bash -c 'until LANG=C chroot $0 umount /proc; do sleep 1; done' $FILESYSTEM_ROOT || true
 
     sudo rm -f $TARGET_PATH/$RFS_SQUASHFS_NAME
     sudo mksquashfs $FILESYSTEM_ROOT $TARGET_PATH/$RFS_SQUASHFS_NAME -Xcompression-level 1
diff --git a/slave.mk b/slave.mk
index 51736f8705d1..8f17fd98b69a 100644
--- a/slave.mk
+++ b/slave.mk
@@ -1264,6 +1264,7 @@ $(addprefix $(TARGET_PATH)/, $(SONIC_RFS_TARGETS)) : $(TARGET_PATH)/% : \
 		export sonicadmin_user="$(USERNAME)"
 		export sonic_asic_platform="$(patsubst %-$(CONFIGURED_ARCH),%,$(CONFIGURED_PLATFORM))"
 		export RFS_SPLIT_FIRST_STAGE=y
+		export RFS_SPLIT_LAST_STAGE=n
 
 		j2 -f env files/initramfs-tools/union-mount.j2 onie-image.conf > files/initramfs-tools/union-mount
 		j2 -f env files/initramfs-tools/arista-convertfs.j2 onie-image.conf > files/initramfs-tools/arista-convertfs