diff --git a/modules/field/field.info.class.inc b/modules/field/field.info.class.inc
index 772cd45..25c1023 100644
--- a/modules/field/field.info.class.inc
+++ b/modules/field/field.info.class.inc
@@ -625,7 +625,9 @@ class FieldInfo {
         $display['type'] = $field_type_info['default_formatter'];
         $formatter_type_info = field_info_formatter_types($display['type']);
       }
-      $display['module'] = $formatter_type_info['module'];
+      if ($formatter_type_info) {
+        $display['module'] = $formatter_type_info['module'];
+      }
       // Fill in default settings for the formatter.
       $display['settings'] += field_info_formatter_settings($display['type']);
     }