diff --git a/scripts/pnglibconf.dfa b/scripts/pnglibconf.dfa
index fe8e481..ecaffe7 100644
--- a/scripts/pnglibconf.dfa
+++ b/scripts/pnglibconf.dfa
@@ -516,8 +516,8 @@ setting USER_WIDTH_MAX default        1000000
 setting USER_HEIGHT_MAX default       1000000

 # Use 0 for unlimited
-setting USER_CHUNK_CACHE_MAX default     1000
-setting USER_CHUNK_MALLOC_MAX default 8000000
+setting USER_CHUNK_CACHE_MAX default  0
+setting USER_CHUNK_MALLOC_MAX default 0

 # If this option is enabled APIs to set the above limits at run time are added;
 # without this the hardwired (compile time) limits will be used.