diff --git a/ChangeLog b/ChangeLog
index 3b7c3abbe..9c23c4178 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+= mbed TLS 1.3.x
+
+Bugfix
+   * Fix an issue that caused valid certificates being rejected whenever an
+   expired or not yet valid version of the trusted certificate was before the
+   valid version in the trusted certificate list.
+
 = mbed TLS 1.3.17 branch 2016-06-28
 
 Security
diff --git a/library/x509_crt.c b/library/x509_crt.c
index 5a15c74fd..b7c73df1d 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -1823,6 +1823,16 @@ static int x509_crt_verify_top(
             continue;
         }
 
+        if( x509_time_expired( &trust_ca->valid_to ) )
+        {
+            continue;
+        }
+
+        if( x509_time_future( &trust_ca->valid_from ) )
+        {
+            continue;
+        }
+
         if( pk_verify_ext( child->sig_pk, child->sig_opts, &trust_ca->pk,
                            child->sig_md, hash, md_info->size,
                            child->sig.p, child->sig.len ) != 0 )
@@ -1854,12 +1864,6 @@ static int x509_crt_verify_top(
         ((void) ca_crl);
 #endif
 
-        if( x509_time_expired( &trust_ca->valid_to ) )
-            ca_flags |= BADCERT_EXPIRED;
-
-        if( x509_time_future( &trust_ca->valid_from ) )
-            ca_flags |= BADCERT_FUTURE;
-
         if( NULL != f_vrfy )
         {
             if( ( ret = f_vrfy( p_vrfy, trust_ca, path_cnt + 1,