diff --git a/src/main/java/org/fiware/iam/Application.java b/src/main/java/org/fiware/iam/Application.java
index c251e30..63e7afe 100644
--- a/src/main/java/org/fiware/iam/Application.java
+++ b/src/main/java/org/fiware/iam/Application.java
@@ -173,7 +173,7 @@ private static PrivateKey loadPrivateKey(String keyType, String filename) {
 
     private static List<X509Certificate> loadCertificates(String resource) {
 
-        try (InputStream is = Application.class.getClassLoader().getResourceAsStream(resource)) {
+        try (InputStream is = openInputStream(resource)) {
             CertificateFactory cf = CertificateFactory.getInstance("X.509");
             Collection<? extends Certificate> certs = cf.generateCertificates(is);