diff --git a/ANNOUNCE b/ANNOUNCE
index 960b0eb..4d2f50b 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -56,7 +56,8 @@
   Removed a redundant test (suggested by "irwir" in Github issue #180).
 
 Version 1.6.33rc02 [September 22, 2017]
-  Added interlaced versions of each file in contrib/pngsuite.
+  Added an interlaced version of each file in contrib/pngsuite.
+  Relocate new memset() call in pngrutil.c.
 
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diff --git a/CHANGES b/CHANGES
index c775213..65e4cb3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -6026,7 +6026,8 @@
   Removed a redundant test (suggested by "irwir" in Github issue #180).
 
 Version 1.6.33rc02 [September 22, 2017]
-  Added interlaced versions of each file in contrib/pngsuite.
+  Added an interlaced version of each file in contrib/pngsuite.
+  Relocate new memset() call in pngrutil.c.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/pngrutil.c b/pngrutil.c
index eb6dc6a..fb6d6b7 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -671,10 +671,11 @@
                    (terminate != 0);
                png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr,
                    buffer_size));
-               memset(text, 0, buffer_size);
 
                if (text != NULL)
                {
+                  memset(text, 0, buffer_size);
+
                   ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
                       png_ptr->read_buffer + prefix_size, &lzsize,
                       text + prefix_size, newlength);