diff --git a/library/x509.c b/library/x509.c
index 60e1cac..0e00ef3 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -735,7 +735,7 @@
  */
 int x509_self_test( int verbose )
 {
-#if defined(POLARSSL_CERTS_C) && defined(POLARSSL_MD5_C)
+#if defined(POLARSSL_CERTS_C) && defined(POLARSSL_SHA1_C)
     int ret;
     int flags;
     x509_crt cacert;