diff --git a/scripts/pnglibconf.dfa b/scripts/pnglibconf.dfa
index 315045106..82cc9a726 100644
--- a/scripts/pnglibconf.dfa
+++ b/scripts/pnglibconf.dfa
@@ -163,8 +163,9 @@ setting API_RULE default 0
 
 # This allows a prefix to be added to the front of every API functon name (and
 # therefore every symbol) by redefining all the function names with the prefix
-# in a new file "pngprefix.h"; this file must be installed in png.h if this
-# facility is used.
+# at the end of pnglibconf.h.  It also turns on similar internal symbol renaming
+# by causing a similar build-time only file, pngprefix.h, to be generated.
+
 setting PREFIX
 
 # Default to using the read macros