diff --git a/core/src/main/java/com/onelogin/saml2/settings/SettingsBuilder.java b/core/src/main/java/com/onelogin/saml2/settings/SettingsBuilder.java
index aec3d6ea..ee46a8ca 100644
--- a/core/src/main/java/com/onelogin/saml2/settings/SettingsBuilder.java
+++ b/core/src/main/java/com/onelogin/saml2/settings/SettingsBuilder.java
@@ -950,7 +950,10 @@ private List<X509Certificate> loadCertificateListFromProp(String propertyKey) {
 			if (propValue == null)
 				break;
 
-			list.add(loadCertificateFromProp(propValue));
+			X509Certificate cert = loadCertificateFromProp(propValue);
+
+			if (cert != null)
+				list.add(cert);
 		}
 
 		return list;