diff --git a/zlib/ChangeLog.gcj b/zlib/ChangeLog.gcj
index a55a024a06c..5c009a8b05d 100644
--- a/zlib/ChangeLog.gcj
+++ b/zlib/ChangeLog.gcj
@@ -1,3 +1,9 @@
+2004-04-10  Kelley Cook  <kcook@gcc.gnu.org>
+
+	* configure.in: Rename file to ...
+	* configure.ac: ...this.
+	* Makefile.in: Regenerate.
+
 2004-04-09  Nathanael Nerode  <neroden@gcc.gnu.org>
 
 	* configure.in: Update to autoconf 2.59; clean up slightly.
diff --git a/zlib/Makefile.in b/zlib/Makefile.in
index 45418aac1bc..117d1e6b0d2 100644
--- a/zlib/Makefile.in
+++ b/zlib/Makefile.in
@@ -184,7 +184,7 @@ LTCOMPILE = $(LIBTOOL) --mode=compile $(CC) $(DEFS) $(INCLUDES) $(AM_CPPFLAGS) $
 CCLD = $(CC)
 LINK = $(LIBTOOL) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@
 DIST_COMMON =  README ChangeLog Makefile.am Makefile.in acinclude.m4 \
-aclocal.m4 configure configure.in
+aclocal.m4 configure configure.ac
 
 
 DISTFILES = $(DIST_COMMON) $(SOURCES) $(HEADERS) $(TEXINFOS) $(EXTRA_DIST)
@@ -197,19 +197,19 @@ OBJECTS = $(libz_a_OBJECTS) $(libzgcj_convenience_la_OBJECTS)
 all: all-redirect
 .SUFFIXES:
 .SUFFIXES: .S .c .lo .o .obj .s
-$(srcdir)/Makefile.in: @MAINTAINER_MODE_TRUE@ Makefile.am $(top_srcdir)/configure.in $(ACLOCAL_M4) 
+$(srcdir)/Makefile.in: @MAINTAINER_MODE_TRUE@ Makefile.am $(top_srcdir)/configure.ac $(ACLOCAL_M4) 
 	cd $(top_srcdir) && $(AUTOMAKE) --cygnus Makefile
 
 Makefile: $(srcdir)/Makefile.in  $(top_builddir)/config.status
 	cd $(top_builddir) \
 	  && CONFIG_FILES=$@ CONFIG_HEADERS= $(SHELL) ./config.status
 
-$(ACLOCAL_M4): @MAINTAINER_MODE_TRUE@ configure.in  acinclude.m4
+$(ACLOCAL_M4): @MAINTAINER_MODE_TRUE@ configure.ac  acinclude.m4
 	cd $(srcdir) && $(ACLOCAL)
 
 config.status: $(srcdir)/configure $(CONFIG_STATUS_DEPENDENCIES)
 	$(SHELL) ./config.status --recheck
-$(srcdir)/configure: @MAINTAINER_MODE_TRUE@$(srcdir)/configure.in $(ACLOCAL_M4) $(CONFIGURE_DEPENDENCIES)
+$(srcdir)/configure: @MAINTAINER_MODE_TRUE@$(srcdir)/configure.ac $(ACLOCAL_M4) $(CONFIGURE_DEPENDENCIES)
 	cd $(srcdir) && $(AUTOCONF)
 
 mostlyclean-toolexeclibLIBRARIES:
diff --git a/zlib/configure.in b/zlib/configure.ac
similarity index 100%
rename from zlib/configure.in
rename to zlib/configure.ac