diff --git a/Makefile.in b/Makefile.in
index 7aac403..9bbe820 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -141,6 +141,9 @@ address@hidden@
 # and ${etcdir} are subdirectories of this.
 address@hidden@
 
+# Where to install C sources of builtin functions.
address@hidden@
+
 # Where to install and expect the files that Emacs modifies as it
 # runs.  These files are all architecture-independent.
 # Right now, this is not used.
@@ -460,7 +463,7 @@ $(srcdir)/src/stamp-h.in: $(AUTOCONF_INPUTS)
 
 # ==================== Installation ====================
 
-.PHONY: install install-arch-dep install-arch-indep install-etcdoc install-info
+.PHONY: install install-arch-dep install-arch-indep install-builtin-src install-etcdoc install-info
 .PHONY: install-man install-etc install-strip install-$(NTDIR)
 .PHONY: uninstall uninstall-$(NTDIR)
 
@@ -468,7 +471,7 @@ $(srcdir)/src/stamp-h.in: $(AUTOCONF_INPUTS)
 ## don't have to duplicate the list of utilities to install in
 ## this Makefile as well.
 
-install: all install-arch-indep install-etcdoc install-arch-dep install-$(NTDIR) blessmail
+install: all install-arch-indep install-builtin-src install-etcdoc install-arch-dep install-$(NTDIR) blessmail
 	@true
 
 ## Ensure that $subdir contains a subdirs.el file.
@@ -504,6 +507,14 @@ else
 	rm -rf ${ns_appresdir}/share
 endif
 
+### Copy C sources of builtin function to the destination dir, so
+### users can view the source code of C functions with `find-file'.
+install-builtin-src:
+ifneq (${builtinsrcdir},)
+	${MKDIR_P} "${builtinsrcdir}"
+	cp ${srcdir}/src/*.{c,h} "${builtinsrcdir}"
+endif
+
 ### Windows-specific install target for installing programs produced
 ### in nt/, and its Posix do-nothing shadow.
 install-:
diff --git a/configure.ac b/configure.ac
index e750a43..8b45007 100644
--- a/configure.ac
+++ b/configure.ac
@@ -196,6 +196,7 @@ dnl hence the single quotes.  This is per the GNU coding standards, see
 dnl (autoconf) Installation Directory Variables
 dnl See also epaths.h below.
 lispdir='${datadir}/emacs/${version}/lisp'
+builtinsrcdir='${datadir}/emacs/${version}/src'
 standardlisppath='${lispdir}'
 locallisppath='${datadir}/emacs/${version}/site-lisp:'\
 '${datadir}/emacs/site-lisp'
@@ -410,6 +411,13 @@ case ${with_gameuser} in
   *) gameuser=${with_gameuser} ;;
 esac
 
+OPTION_DEFAULT_OFF([builtin-sources],[install C sources of built-in functions])
+
+echo "with builtin sources: $with_builtin_sources"
+if test $with_builtin_sources != "yes"; then
+   builtinsrcdir=
+fi
+
 AC_ARG_WITH([gnustep-conf],dnl
 [AS_HELP_STRING([--with-gnustep-conf=FILENAME],
    [name of GNUstep configuration file to use on systems where the command
@@ -4876,6 +4884,7 @@ AC_SUBST(libexecdir)
 AC_SUBST(mandir)
 AC_SUBST(infodir)
 AC_SUBST(lispdir)
+AC_SUBST(builtinsrcdir)
 AC_SUBST(standardlisppath)
 AC_SUBST(locallisppath)
 AC_SUBST(lisppath)