diff --git a/collects/openssl/mzssl.ss b/collects/openssl/mzssl.ss
index 585346c5d9..f1ba3412d6 100644
--- a/collects/openssl/mzssl.ss
+++ b/collects/openssl/mzssl.ss
@@ -44,6 +44,7 @@
 	   ssl-connect
 	   ssl-connect/enable-break
 
+	   ssl-listener?
 	   ssl-addresses
 	   ssl-abandon-port)