diff --git a/ANNOUNCE b/ANNOUNCE
index 2734d9160..5ef85666a 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.5.20rc01 - November 13, 2014
+Libpng 1.5.20rc02 - November 14, 2014
 
 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.
@@ -9,21 +9,21 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.5.20rc01.tar.xz (LZMA-compressed, recommended)
-   1.5.20rc01.tar.gz
-   1.5.20rc01.tar.bz2
+   1.5.20rc02.tar.xz (LZMA-compressed, recommended)
+   1.5.20rc02.tar.gz
+   1.5.20rc02.tar.bz2
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp1520r01.7z  (LZMA-compressed, recommended)
-   lp1520r01.zip
+   lp1520r02.7z  (LZMA-compressed, recommended)
+   lp1520r02.zip
 
 Other information:
 
-   1.5.20rc01-README.txt
-   1.5.20rc01-LICENSE.txt
-   libpng-1.5.20rc01-*.asc (armored detached GPG signatures)
+   1.5.20rc02-README.txt
+   1.5.20rc02-LICENSE.txt
+   libpng-1.5.20rc02-*.asc (armored detached GPG signatures)
 
 Changes since the last public release (1.5.19):
 
@@ -39,6 +39,12 @@ Version 1.5.20beta02 [November 10, 2014]
 
 Version 1.5.20rc01 [November 13, 2014]
 
+Version 1.5.20rc02 [November 14, 2014]
+  The macros passed in the command line to Borland make are ignored if
+    similarly-named macros are already defined in makefiles. This behavior
+    is different from POSIX make and other make programs.  Surround the
+    macro definitions with ifndef guards (Cosmin).
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
diff --git a/CHANGES b/CHANGES
index b89ad8f9a..65dca356f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4258,6 +4258,12 @@ Version 1.5.20beta02 [November 10, 2014]
 
 Version 1.5.20rc01 [November 13, 2014]
 
+Version 1.5.20rc02 [November 14, 2014]
+  The macros passed in the command line to Borland make are ignored if
+    similarly-named macros are already defined in makefiles. This behavior
+    is different from POSIX make and other make programs.  Surround the
+    macro definitions with ifndef guards (Cosmin).
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
diff --git a/scripts/makefile.bc32 b/scripts/makefile.bc32
index d488a54a0..bdbc4cb2f 100644
--- a/scripts/makefile.bc32
+++ b/scripts/makefile.bc32
@@ -52,7 +52,9 @@ LDFLAGS=-L$(ZLIB_DIR) -M $(LDEBUG)
 
 # Pre-built configuration
 # See scripts\pnglibconf.mak for more options
+!ifndef PNGLIBCONF_H_PREBUILT
 PNGLIBCONF_H_PREBUILT = scripts\pnglibconf.h.prebuilt
+!endif
 
 ## Variables
 OBJS = \
diff --git a/scripts/makefile.bor b/scripts/makefile.bor
index a01f73899..6693772db 100644
--- a/scripts/makefile.bor
+++ b/scripts/makefile.bor
@@ -60,7 +60,9 @@ LDFLAGS=-M -L$(ZLIB_DIR) $(MODEL_ARG) $(LDEBUG)
 
 # Pre-built configuration
 # See scripts\pnglibconf.mak for more options
+!ifndef PNGLIBCONF_H_PREBUILT
 PNGLIBCONF_H_PREBUILT = scripts\pnglibconf.h.prebuilt
+!endif
 
 ## Variables
 
diff --git a/scripts/makefile.tc3 b/scripts/makefile.tc3
index c917a08f1..1d015026c 100644
--- a/scripts/makefile.tc3
+++ b/scripts/makefile.tc3
@@ -16,7 +16,9 @@ CP=copy
 
 # Pre-built configuration
 # See scripts\pnglibconf.mak for more options
+!ifndef PNGLIBCONF_H_PREBUILT
 PNGLIBCONF_H_PREBUILT = scripts\pnglibconf.h.prebuilt
+!endif
 
 O=.obj
 E=.exe