diff --git a/docs/cmdline-opts/_EXITCODES.md b/docs/cmdline-opts/_EXITCODES.md
index d7b71fda0d..c5a928b590 100644
--- a/docs/cmdline-opts/_EXITCODES.md
+++ b/docs/cmdline-opts/_EXITCODES.md
@@ -196,6 +196,8 @@ Proxy handshake error.
 A client-side certificate is required to complete the TLS handshake.
 ## 99
 Poll or select returned fatal error.
+## 100
+A value or data field grew larger than allowed.
 ## XX
 More error codes might appear here in future releases. The existing ones are
 meant to never change.