diff --git a/tools/make_metadata.py b/tools/make_metadata.py
index 67ecbd0..b9f883c 100755
--- a/tools/make_metadata.py
+++ b/tools/make_metadata.py
@@ -4,6 +4,7 @@ import getopt
 
 from saml2.metadata import entity_descriptor, entities_descriptor
 from saml2.sigver import SecurityContext
+from saml2.validate import valid_instance
 
 HELP_MESSAGE = """
 Usage: make_metadata [options] 1*configurationfile
@@ -72,7 +73,9 @@ def main(args):
         eds.append(entity_descriptor(confd, valid_for))
     
     secc = SecurityContext(xmlsec, keyfile) 
-    print entities_descriptor(eds, valid_for, name, id, sign, secc)
+    desc = entities_descriptor(eds, valid_for, name, id, sign, secc)
+    valid_instance(desc)
+    print desc
     
 if __name__ == "__main__":
     import sys