diff --git a/library/error.c b/library/error.c
index 4718b51..4bd15bf 100644
--- a/library/error.c
+++ b/library/error.c
@@ -183,6 +183,8 @@
             mbedtls_snprintf( buf, buflen, "CIPHER - Decryption of block requires a full block" );
         if( use_ret == -(MBEDTLS_ERR_CIPHER_AUTH_FAILED) )
             mbedtls_snprintf( buf, buflen, "CIPHER - Authentication failed (for AEAD modes)" );
+        if( use_ret == -(MBEDTLS_ERR_CIPHER_INVALID_CONTEXT) )
+            mbedtls_snprintf( buf, buflen, "CIPHER - The context is invalid, eg because it was free()ed" );
 #endif /* MBEDTLS_CIPHER_C */
 
 #if defined(MBEDTLS_DHM_C)