diff --git a/ChangeLog b/ChangeLog
index 02397e8e33c..c4e57e4808c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2002-12-18  H.J. Lu <hjl@gnu.org>
+
+	* Makefile.tpl: Add @build_prefix@ before $(BUILD_SUBDIR).
+	* Makefile.in: Regenerated.
+
+	* configure.in (build_prefix): New. Substitute.
+
 2002-12-18  Nathanael Nerode  <neroden@gcc.gnu.org>
 
 	* Makefile.tpl: Don't let real targets depend on phony targets.
diff --git a/Makefile.in b/Makefile.in
index 400c875fcd5..a2265d4b61d 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -1234,7 +1234,7 @@ TAGS: do-TAGS
 .PHONY: configure-build-libiberty maybe-configure-build-libiberty
 maybe-configure-build-libiberty:
 configure-build-libiberty: $(BUILD_SUBDIR)/libiberty/Makefile
-$(BUILD_SUBDIR)/libiberty/Makefile: config.status
+@build_prefix@$(BUILD_SUBDIR)/libiberty/Makefile: config.status
 	@[ -d $(BUILD_SUBDIR)/libiberty ] || mkdir $(BUILD_SUBDIR)/libiberty;\
 	    r=`${PWD}`; export r; \
 	    s=`cd $(srcdir); ${PWD}`; export s; \
diff --git a/Makefile.tpl b/Makefile.tpl
index 1a758859c4c..d656c5065d5 100644
--- a/Makefile.tpl
+++ b/Makefile.tpl
@@ -791,7 +791,7 @@ TAGS: do-TAGS
 .PHONY: configure-build-[+module+] maybe-configure-build-[+module+]
 maybe-configure-build-[+module+]:
 configure-build-[+module+]: $(BUILD_SUBDIR)/[+module+]/Makefile
-$(BUILD_SUBDIR)/[+module+]/Makefile: config.status
+@build_prefix@$(BUILD_SUBDIR)/[+module+]/Makefile: config.status
 	@[ -d $(BUILD_SUBDIR)/[+module+] ] || mkdir $(BUILD_SUBDIR)/[+module+];\
 	    r=`${PWD}`; export r; \
 	    s=`cd $(srcdir); ${PWD}`; export s; \
diff --git a/configure.in b/configure.in
index f16fe5baacb..fb379fcfda6 100644
--- a/configure.in
+++ b/configure.in
@@ -168,6 +168,10 @@ if test x"${build_alias}" != x"${host}" ; then
   fi
 fi
 
+if test x"${target_subdir}" = x"${build_subdir}" ; then
+  build_prefix=build-
+fi
+
 # Skipdirs are removed silently.
 skipdirs=
 # Noconfigdirs are removed loudly.
@@ -1729,6 +1733,7 @@ s%@CXX_FOR_TARGET_FOR_RECURSIVE_MAKE@%\$(STAGE_CC_WRAPPER) ${qqCXX_FOR_TARGET}%
 s%@RAW_CXX_FOR_TARGET_FOR_RECURSIVE_MAKE@%\$(STAGE_CC_WRAPPER) ${qqRAW_CXX_FOR_TARGET}%
 s%@target_subdir@%${target_subdir}%
 s%@build_subdir@%${build_subdir}%
+s%@build_prefix@%${build_prefix}%
 s%@build_configargs@%${buildargs}%
 s%@gxx_include_dir@%${gxx_include_dir}%
 s%@host_configargs@%${hostargs}%