Address user reported coverity issues.
diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index 70000f5..c967554 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -57,6 +57,7 @@
#define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200 /**< Input data contains invalid padding and is rejected. */
#define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280 /**< Decryption of block requires a full block. */
#define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300 /**< Authentication failed (for AEAD modes). */
+#define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380 /**< The context is invalid, eg because it was free()ed. */
#define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length */
#define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length */