diff --git a/DeDRM_plugin/__init__.py b/DeDRM_plugin/__init__.py
index b27fde9..cb981d8 100644
--- a/DeDRM_plugin/__init__.py
+++ b/DeDRM_plugin/__init__.py
@@ -421,7 +421,7 @@ class DeDRM(FileTypePlugin):
         # Attempt to decrypt epub with each encryption key (generated or provided).
         print("{0} v{1}: {2} is a PDF ebook".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
         for keyname, userkeyhex in dedrmprefs['adeptkeys'].items():
-            userkey = userkeyhex.decode('hex')
+            userkey = codecs.decode(userkeyhex,'hex')
             print("{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname))
             of = self.temporary_file(".pdf")
 
@@ -467,7 +467,7 @@ class DeDRM(FileTypePlugin):
 
         newkeys = []
         for keyvalue in defaultkeys:
-            if keyvalue.encode('hex') not in dedrmprefs['adeptkeys'].values():
+            if codecs.encode(keyvalue,'hex') not in dedrmprefs['adeptkeys'].values():
                 newkeys.append(keyvalue)
 
         if len(newkeys) > 0:
@@ -491,7 +491,7 @@ class DeDRM(FileTypePlugin):
                         # Store the new successful key in the defaults
                         print("{0} v{1}: Saving a new default key".format(PLUGIN_NAME, PLUGIN_VERSION))
                         try:
-                            dedrmprefs.addnamedvaluetoprefs('adeptkeys','default_key',keyvalue.encode('hex'))
+                            dedrmprefs.addnamedvaluetoprefs('adeptkeys','default_key',codecs.encode(keyvalue,'hex'))
                             dedrmprefs.writeprefs()
                             print("{0} v{1}: Saved a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
                         except:
@@ -596,7 +596,7 @@ class DeDRM(FileTypePlugin):
             of = self.temporary_file(".pmlz")
 
             # Give the userkey, ebook and TemporaryPersistent file to the decryption function.
-            result = erdr2pml.decryptBook(path_to_ebook, of.name, True, userkey.decode('hex'))
+            result = erdr2pml.decryptBook(path_to_ebook, of.name, True, codecs.decode(userkey,'hex'))
 
             of.close()