@@ -446,7 +446,9 @@ def simple_principal_to_full(inentry, index, entry):

 				message = 'Invalid or unknown name_type specified in entry #%d'

 				message += '; use name_type_raw to enforce an arbitrary value'

 				raise KeytabParsingError(message % index)

-		entry['spn'] = principal_to_spn(principal)

+		spn = principal_to_spn(principal)

+		if spn:

+			entry['spn'] = spn

 	elif 'spn' in inentry:

 		entry['spn'] = inentry['spn']

 		entry['principal'] = spn_to_principal(inentry['spn'])