diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index d9b05fd..23165a4 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5833,6 +5833,9 @@
     if( hostname_len + 1 == 0 )
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 
+    if( hostname_len > MBEDTLS_SSL_MAX_HOST_NAME )
+        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
     ssl->hostname = mbedtls_calloc( 1, hostname_len + 1 );
 
     if( ssl->hostname == NULL )