2 files changed, 12 insertions, 5 deletions
diff --git a/doc/ssl/SSL_get_error.pod b/doc/ssl/SSL_get_error.pod
index 2a93894096e7..7537616d475c 100644
--- a/doc/ssl/SSL_get_error.pod
+++ b/doc/ssl/SSL_get_error.pod
@@ -90,14 +90,17 @@ Details depend on the application.
 
 =item SSL_ERROR_SYSCALL
 
-Some non-recoverable I/O error occurred.
-The OpenSSL error queue may contain more information on the error.
-For socket I/O on Unix systems, consult B<errno> for details.
+Some non-recoverable, fatal I/O error occurred. The OpenSSL error queue may
+contain more information on the error. For socket I/O on Unix systems, consult
+B<errno> for details. If this error occurs then no further I/O operations should
+be performed on the connection and SSL_shutdown() must not be called.
 
 =item SSL_ERROR_SSL
 
-A failure in the SSL library occurred, usually a protocol error.  The
-OpenSSL error queue contains more information on the error.
+A non-recoverable, fatal error in the SSL library occurred, usually a protocol
+error.  The OpenSSL error queue contains more information on the error. If this
+error occurs then no further I/O operations should be performed on the
+connection and SSL_shutdown() must not be called.
 
 =back
 
diff --git a/doc/ssl/SSL_shutdown.pod b/doc/ssl/SSL_shutdown.pod
index efbff5a0a323..e2a776cf1c73 100644
--- a/doc/ssl/SSL_shutdown.pod
+++ b/doc/ssl/SSL_shutdown.pod
@@ -22,6 +22,10 @@ Whether the operation succeeds or not, the SSL_SENT_SHUTDOWN flag is set and
 a currently open session is considered closed and good and will be kept in the
 session cache for further reuse.
 
+Note that SSL_shutdown() must not be called if a previous fatal error has
+occurred on a connection i.e. if SSL_get_error() has returned SSL_ERROR_SYSCALL
+or SSL_ERROR_SSL.
+
 The shutdown procedure consists of 2 steps: the sending of the "close notify"
 shutdown alert and the reception of the peer's "close notify" shutdown
 alert. According to the TLS standard, it is acceptable for an application