diff --git a/uuid.tokens.inc b/uuid.tokens.inc
index c1183a4..c68be47 100644
--- a/uuid.tokens.inc
+++ b/uuid.tokens.inc
@@ -34,9 +34,9 @@ function uuid_tokens($token_type, $tokens, $data = array(), $options = array())
   $replacements = array();
   if ($token_type == 'entity') {
     $info = entity_get_info($data['entity_type']);
-    if (isset($info['uuid']) && $info['uuid'] == TRUE && !empty($info['entity keys']['uuid'])) {
+    if (isset($info['uuid']) && $info['uuid'] == TRUE && !empty($info['entity keys']['uuid']) && isset($tokens[$info['entity keys']['uuid']])) {
       $replacements[$tokens[$info['entity keys']['uuid']]] = $data['entity']->{$info['entity keys']['uuid']};
-      if (!empty($info['entity keys']['revision uuid'])) {
+      if (!empty($info['entity keys']['revision uuid']) && isset($tokens[$info['entity keys']['revision uuid']])) {
         $replacements[$tokens[$info['entity keys']['revision uuid']]] = $data['entity']->{$info['entity keys']['revision uuid']};
       }
     }