diff --git a/ANNOUNCE b/ANNOUNCE
index 7b71f1874..3d462aff6 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -28,8 +28,10 @@ Changes since the last public release (1.5.2):
 
 Version 1.5.3beta01 [April 1, 2011]
   Re-initialize the zlib compressor before compressing non-IDAT chunks.
+  Added API functions to set parameters for zlib compression of non-IDAT chunks.
 
 Version 1.5.3beta02 [April 1, 2011]
+  Updated scripts/symbols.def with new API functions.
 
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diff --git a/CHANGES b/CHANGES
index 98f9f643c..0a98aa771 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3289,8 +3289,10 @@ Version 1.5.2 [March 31, 2011]
 
 Version 1.5.3beta01 [April 1, 2011]
   Re-initialize the zlib compressor before compressing non-IDAT chunks.
+  Added API functions to set parameters for zlib compression of non-IDAT chunks.
 
 Version 1.5.3beta02 [April 1, 2011]
+  Updated scripts/symbols.def with new API functions.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/scripts/symbols.def b/scripts/symbols.def
index 07c61ef80..e81472885 100644
--- a/scripts/symbols.def
+++ b/scripts/symbols.def
@@ -227,3 +227,8 @@ EXPORTS
  png_process_data_pause @219
  png_process_data_skip @220
  png_set_expand_16 @221
+ png_set_text_compression_level @222
+ png_set_text_compression_mem_level @223
+ png_set_text_compression_strategy @224
+ png_set_text_compression_window_bits @225
+ png_set_text_compression_level @226