diff --git a/library/x509_crt.c b/library/x509_crt.c
index 6b5ac08..c9a7c5c 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -3500,6 +3500,8 @@
 {
     mbedtls_x509_crt *cert_cur = crt;
     mbedtls_x509_crt *cert_prv;
+    mbedtls_x509_sequence *seq_cur;
+    mbedtls_x509_sequence *seq_prv;
 
     while( cert_cur != NULL )
     {