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 */