diff --git a/ANNOUNCE b/ANNOUNCE
index 7379e8d02..15a917503 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.5.0beta48 - September 11, 2010
+Libpng 1.5.0beta48 - September 14, 2010
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -226,7 +226,7 @@ version 1.5.0beta24 [May 7, 2010]
     offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf.
   Added more blank lines for readability.
 
-version 1.5.0beta25 [September 11, 2010]
+version 1.5.0beta25 [September 14, 2010]
   In pngpread.c: png_push_have_row() add check for new_row > height
   Removed the now-redundant check for out-of-bounds new_row from example.c
 
@@ -397,7 +397,10 @@ Version 1.5.0beta47 [September 11, 2010]
   Fixed a number of problems with 64-bit compilation reported by Visual
     Studio 2010 (John Bowler).
 
-Version 1.5.0beta48 [September 11, 2010]
+Version 1.5.0beta48 [September 14, 2010]
+  Updated CMakeLists.txt (Philip Lowman).
+  Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
+    $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
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diff --git a/CHANGES b/CHANGES
index c327b74cf..cd5d2e469 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3034,7 +3034,10 @@ Version 1.5.0beta47 [September 11, 2010]
   Fixed a number of problems with 64-bit compilation reported by Visual
     Studio 2010 (John Bowler).
 
-Version 1.5.0beta48 [September 11, 2010]
+Version 1.5.0beta48 [September 14, 2010]
+  Updated CMakeLists.txt (Philip Lowman).
+  Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
+    $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/autogen.sh b/autogen.sh
index d63744b98..5be104eb1 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -4,22 +4,31 @@
 #
 # WARNING: if you run this you will change the versions
 # of the tools which are used and, maybe, required!
+
+# You can define your own replacements in your environment.
+# $AUTOCONF,  $AUTOMAKE, $AUTOHEADER, $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
+
 touch Makefile.am configure.ac
 {
-   echo "running libtoolize" >&2
-   libtoolize --force --copy --automake
+   LT=${LIBTOOLIZE-libtoolize}
+   echo "running $LT" >&2
+   $LT --force --copy --automake
 } && {
-   echo "running aclocal" >&2
-   aclocal
+   AL=${ACLOCAL-aclocal}
+   echo "running $AL" >&2
+   $AL
 } && {
-   echo "running autoheader [ignore the warnings]" >&2
-   autoheader
+   AH=${AUTOHEADER-autoheader}
+   echo "running $AH [ignore the warnings]" >&2
+   $AH
 } && {
-   echo "running automake" >&2
-   automake --force-missing --foreign -a -c
+   AM=${AUTOMAKE-automake}
+   echo "running $AM" >&2
+   $AM --force-missing --foreign -a -c
 } && {
-   echo "running autoconf" >&2
-   autoconf
+   AC=${AUTOCONF-autoconf}
+   echo "running $AC" >&2
+   $AC
 } &&
    echo "autogen complete" >&2 ||
    echo "ERROR: autogen.sh failed, autogen is incomplete" >&2