diff --git a/ChangeLog b/ChangeLog
index 79f596d0a..60018b557 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -63,7 +63,15 @@ Changes
    * Reduce RAM consumption during session renegotiation by not storing
      the peer CRT chain and session ticket twice.
 
-= mbed TLS 2.16.x branch released xxxx-xx-xx
+= mbed TLS 2.16.5 branch released xxxx-xx-xx
+
+Security
+   * Fix potential memory overread when performing an ECDSA signature
+     operation. The overread only happens with cryptographically low
+     probability (of the order of 2^-n where n is the bitsize of the curve)
+     unless the RNG is broken, and could result in information disclosure or
+     denial of service (application crash or extra resource consumption).
+     Reported by Peter and Auke (found using static analysis).
 
 Bugfix
    * Fix an unchecked call to mbedtls_md() in the x509write module.
diff --git a/library/ecdsa.c b/library/ecdsa.c
index 657778594..6cfaa08fe 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -297,7 +297,7 @@ static int ecdsa_sign_restartable( mbedtls_ecp_group *grp,
     *p_sign_tries = 0;
     do
     {
-        if( *p_sign_tries++ > 10 )
+        if( (*p_sign_tries)++ > 10 )
         {
             ret = MBEDTLS_ERR_ECP_RANDOM_FAILED;
             goto cleanup;
@@ -310,7 +310,7 @@ static int ecdsa_sign_restartable( mbedtls_ecp_group *grp,
         *p_key_tries = 0;
         do
         {
-            if( *p_key_tries++ > 10 )
+            if( (*p_key_tries)++ > 10 )
             {
                 ret = MBEDTLS_ERR_ECP_RANDOM_FAILED;
                 goto cleanup;