diff --git a/src/libsaml.ts b/src/libsaml.ts
index be872e38..e4a42019 100644
--- a/src/libsaml.ts
+++ b/src/libsaml.ts
@@ -472,7 +472,8 @@ const libSaml = () => {
             metadataCert = [metadataCert];
           }
           metadataCert = metadataCert.map(utility.normalizeCerString);
-          const x509Certificate = select("//*[local-name(.)='X509Certificate']", s)[0].firstChild.data;
+          let x509Certificate = select("//*[local-name(.)='X509Certificate']", s)[0].firstChild.data;
+          x509Certificate = utility.normalizeCerString(x509Certificate);
           if (includes(metadataCert, x509Certificate)) {
             selectedCert = x509Certificate;
           }