diff --git a/library/error.c b/library/error.c
index a2de275..4dc13a4 100644
--- a/library/error.c
+++ b/library/error.c
@@ -499,6 +499,8 @@
             mbedtls_snprintf( buf, buflen, "SSL - Couldn't set the hash for verifying CertificateVerify" );
         if( use_ret == -(MBEDTLS_ERR_SSL_CONTINUE_PROCESSING) )
             mbedtls_snprintf( buf, buflen, "SSL - Internal-only message signaling that further message-processing should be done" );
+        if( use_ret == -(MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS) )
+            mbedtls_snprintf( buf, buflen, "SSL - A cryptographic operation is in progress. Try again later" );
 #endif /* MBEDTLS_SSL_TLS_C */
 
 #if defined(MBEDTLS_X509_USE_C) || defined(MBEDTLS_X509_CREATE_C)