diff --git a/ChangeLog b/ChangeLog
index 4c2b1a1a4..3fd8e0e58 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,10 @@ mbed TLS ChangeLog (Sorted per branch, date)
 
 = mbed TLS 2.x.x branch released xxxx-xx-xx
 
+Security
+   * Removed MD5 from the allowed hash algorithms for CertificateRequest and
+     CertificateVerify messages, to prevent SLOTH attacks against TLS 1.2.
+
 Bugfix
    * Fixed potential arithmetic overflow in mbedtls_ctr_drbg_reseed() that could
      cause buffer bound checks to be bypassed. Found by Eyal Itkin.
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 121c13526..be67bca2b 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -7645,8 +7645,7 @@ int mbedtls_ssl_set_calc_verify_md( mbedtls_ssl_context *ssl, int md )
 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
 #if defined(MBEDTLS_MD5_C)
         case MBEDTLS_SSL_HASH_MD5:
-            ssl->handshake->calc_verify = ssl_calc_verify_tls;
-            break;
+            return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH;
 #endif
 #if defined(MBEDTLS_SHA1_C)
         case MBEDTLS_SSL_HASH_SHA1: