diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 2350910..aaddd7f 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -67,7 +67,7 @@
 #define MBEDTLS_ERR_SSL_INVALID_MAC                       -0x7180  /**< Verification of the message MAC failed. */
 #define MBEDTLS_ERR_SSL_INVALID_RECORD                    -0x7200  /**< An invalid SSL record was received. */
 #define MBEDTLS_ERR_SSL_CONN_EOF                          -0x7280  /**< The connection indicated an EOF. */
-#define MBEDTLS_ERR_SSL_UNKNOWN_CIPHER                    -0x7300  /**< An unknown cipher was received. */
+/* NOTE: Error space gap */
 #define MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN                  -0x7380  /**< The server has no ciphersuites in common with the client. */
 #define MBEDTLS_ERR_SSL_NO_RNG                            -0x7400  /**< No RNG was provided to the SSL module. */
 #define MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE             -0x7480  /**< No client certification received from the client, but required by the authentication mode. */