diff --git a/sylk/tls.py b/sylk/tls.py
index 066c6dd..a147a85 100644
--- a/sylk/tls.py
+++ b/sylk/tls.py
@@ -1,49 +1,49 @@
 
 from application import log
 from application.process import process
 from gnutls.crypto import X509Certificate, X509PrivateKey
 
 
 __all__ = 'Certificate', 'PrivateKey'
 
 
-def file_content(file):
-    path = process.configuration.file(file)
+def file_content(filename):
+    path = process.configuration.file(filename)
     if path is None:
-        raise Exception("File '%s' does not exist" % file)
+        raise Exception("File '%s' does not exist" % filename)
     try:
         f = open(path, 'rt')
     except Exception:
-        raise Exception("File '%s' could not be open" % file)
+        raise Exception("File '%s' could not be open" % filename)
     try:
         return f.read()
     finally:
         f.close()
 
 
 class Certificate(object):
     """Configuration data type. Used to create a gnutls.crypto.X509Certificate object
        from a file given in the configuration file."""
     def __new__(cls, value):
         if isinstance(value, basestring):
             try:
                 return X509Certificate(file_content(value))
             except Exception as e:
                 log.warn("Certificate file '%s' could not be loaded: %s" % (value, str(e)))
                 return None
         else:
             raise TypeError('value should be a string')
 
 
 class PrivateKey(object):
     """Configuration data type. Used to create a gnutls.crypto.X509PrivateKey object
        from a file given in the configuration file."""
     def __new__(cls, value):
         if isinstance(value, basestring):
             try:
                 return X509PrivateKey(file_content(value))
             except Exception as e:
                 log.warn("Private key file '%s' could not be loaded: %s" % (value, str(e)))
                 return None
         else:
             raise TypeError('value should be a string')