diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 73a6604..b3b82b0 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -1991,6 +1991,10 @@
         return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
 
     ssl->hostname_len = strlen( hostname );
+
+    if( ssl->hostname_len + 1 == 0 )
+        return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
     ssl->hostname = (unsigned char *) malloc( ssl->hostname_len + 1 );
 
     if( ssl->hostname == NULL )
@@ -1998,7 +2002,7 @@
 
     memcpy( ssl->hostname, (unsigned char *) hostname,
             ssl->hostname_len );
-    
+
     ssl->hostname[ssl->hostname_len] = '\0';
 
     return( 0 );