diff --git a/Makefile b/Makefile
index 6eafedd7efc6..9f5a3cac63e7 100644
--- a/Makefile
+++ b/Makefile
@@ -1225,7 +1225,7 @@ PHONY += prepare archprepare
 
 archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
 	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
-	include/generated/autoconf.h
+	include/generated/autoconf.h remove-stale-files
 
 prepare0: archprepare
 	$(Q)$(MAKE) $(build)=scripts/mod
@@ -1234,6 +1234,10 @@ prepare0: archprepare
 # All the preparing..
 prepare: prepare0 prepare-objtool prepare-resolve_btfids
 
+PHONY += remove-stale-files
+remove-stale-files:
+	$(Q)$(srctree)/scripts/remove-stale-files
+
 # Support for using generic headers in asm-generic
 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
 
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index fd94e27ba4fa..182b300e3f8a 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -96,13 +96,6 @@ endif
 $(foreach o, $(libfdt_objs) atags_to_fdt.o fdt_check_mem_start.o, \
 	$(eval CFLAGS_$(o) := -I $(srctree)/scripts/dtc/libfdt -fno-stack-protector))
 
-# These were previously generated C files. When you are building the kernel
-# with O=, make sure to remove the stale files in the output tree. Otherwise,
-# the build system wrongly compiles the stale ones.
-ifdef building_out_of_srctree
-$(shell rm -f $(addprefix $(obj)/, fdt_rw.c fdt_ro.c fdt_wip.c fdt.c))
-endif
-
 targets       := vmlinux vmlinux.lds piggy_data piggy.o \
 		 lib1funcs.o ashldi3.o bswapsdi2.o \
 		 head.o $(OBJS)
diff --git a/scripts/remove-stale-files b/scripts/remove-stale-files
new file mode 100755
index 000000000000..c3eb81c3f7de
--- /dev/null
+++ b/scripts/remove-stale-files
@@ -0,0 +1,31 @@
+#!/bin/sh
+
+set -e
+
+# When you move, remove or rename generated files, you probably also update
+# .gitignore and cleaning rules in the Makefile. This is the right thing
+# to do. However, people usually do 'git pull', 'git bisect', etc. without
+# running 'make clean'. Then, the stale generated files are left over, often
+# causing build issues.
+#
+# Also, 'git status' shows such stale build artifacts as untracked files.
+# What is worse, some people send a wrong patch to get them back to .gitignore
+# without checking the commit history.
+#
+# So, when you (re)move generated files, please move the cleaning rules from
+# the Makefile to this script. This is run before Kbuild starts building
+# anything, so people will not be annoyed by such garbage files.
+#
+# This script is not intended to grow endlessly. Rather, it is a temporary scrap
+# yard. Stale files stay in this file for a while (for some release cycles?),
+# then will be really dead and removed from the code base entirely.
+
+# These were previously generated source files. When you are building the kernel
+# with O=, make sure to remove the stale files in the output tree. Otherwise,
+# the build system wrongly compiles the stale ones.
+if [ -n "${building_out_of_srctree}" ]; then
+	for f in fdt_rw.c fdt_ro.c fdt_wip.c fdt.c
+	do
+		rm -f arch/arm/boot/compressed/${f}
+	done
+fi