diff --git a/ANNOUNCE b/ANNOUNCE
index 2ff4e344d..73fadac04 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,4 +1,4 @@
-Libpng 1.6.18beta01 - March 26, 2015
+Libpng 1.6.18beta01 - March 27, 2015
 
 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.
@@ -25,6 +25,10 @@ Other information:
 
 Changes since the last public release (1.6.17):
 
+Version 1.6.18beta01 [March 27, 2015]
+  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
+    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+    bug report by Andrew Church).
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 73fe572a1..fe07211ba 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5205,7 +5205,10 @@ Version 1.6.17rc06 [March 23, 2015]
 Version 1.6.17 [March 26, 2015]
   No changes.
 
-Version 1.6.18beta01 [March 26, 2015]
+Version 1.6.18beta01 [March 27, 2015]
+  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
+    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+    bug report by Andrew Church).
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/pngrutil.c b/pngrutil.c
index 6c5c37526..d2103799e 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -575,7 +575,7 @@ png_decompress_chunk(png_structrp png_ptr,
     */
    png_alloc_size_t limit = PNG_SIZE_MAX;
 
-# ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+# ifdef PNG_SET_USER_LIMITS_SUPPORTED
    if (png_ptr->user_chunk_malloc_max > 0 &&
        png_ptr->user_chunk_malloc_max < limit)
       limit = png_ptr->user_chunk_malloc_max;
@@ -2715,7 +2715,7 @@ png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
       png_ptr->unknown_chunk.data = NULL;
    }
 
-#  ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+#  ifdef PNG_SET_USER_LIMITS_SUPPORTED
       if (png_ptr->user_chunk_malloc_max > 0 &&
           png_ptr->user_chunk_malloc_max < limit)
          limit = png_ptr->user_chunk_malloc_max;
diff --git a/scripts/pnglibconf.h.prebuilt b/scripts/pnglibconf.h.prebuilt
index e95a2fed2..beab039fd 100644
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@@ -2,7 +2,7 @@
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.6.18beta01 - March 26, 2015 */
+/* Libpng version 1.6.18beta01 - March 27, 2015 */
 
 /* Copyright (c) 1998-2014 Glenn Randers-Pehrson */
 
@@ -101,8 +101,6 @@
 #define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SEQUENTIAL_READ_SUPPORTED
 #define PNG_SETJMP_SUPPORTED
-#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
-#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
 #define PNG_SET_OPTION_SUPPORTED
 #define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SET_USER_LIMITS_SUPPORTED