diff --git a/ChangeLog b/ChangeLog
index 3617915..506d96a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -32,6 +32,8 @@
    * Fixed x509_crt_parse_path() bug on Windows platforms
    * Added missing MPI_CHK() around some statements in mpi_div_mpi() (found by
      TrustInSoft)
+   * Fixed potential overflow in certificate size verification in
+     ssl_write_certificate() (found by TrustInSoft)
 
 Security
    * Possible remotely-triggered out-of-bounds memory access fixed (found by
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 6ea2821..e738028 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2453,7 +2453,7 @@
     while( crt != NULL )
     {
         n = crt->raw.len;
-        if( i + 3 + n > SSL_MAX_CONTENT_LEN )
+        if( n > SSL_MAX_CONTENT_LEN - 3 - i )
         {
             SSL_DEBUG_MSG( 1, ( "certificate too large, %d > %d",
                            i + 3 + n, SSL_MAX_CONTENT_LEN ) );