diff --git a/doc/NEWS.Rd b/doc/NEWS.Rd
index d9735141106..8604a6cbae3 100644
--- a/doc/NEWS.Rd
+++ b/doc/NEWS.Rd
@@ -203,6 +203,12 @@
       argument descriptions when they spanned multiple lines,
       including those generated by \code{prompt()}.
       These cases are now noted by \command{R CMD check}.
+
+      \item Communication between parent and child processes in
+      \code{multicore} part of \code{parallel} could fail on platforms
+      that do not support arbitrarily large payload in system functions
+      \code{read()}/\code{write()} on pipes (seen on macOS). The payload
+      is now split into 1Gb chunks to avoid that problem. \PR{18571}
     }
   }
 }