diff --git a/src/Utility.php b/src/Utility.php
index 4eb658f..e416244 100644
--- a/src/Utility.php
+++ b/src/Utility.php
@@ -68,9 +68,11 @@ public static function isTextType($type, array $text_types = array('text')) {
     // @todo Currently, this is useless, but later we could also check
     //   automatically for custom types that have one of the passed types as their
     //   fallback.
-    return in_array($type, $text_types);
+    $default = in_array($type, $text_types);
+    $fallback = in_array($type->getFallbackType(), $text_types);
+    return ($default || $fallback) ? TRUE : FALSE;
   }
-
+

   /**
    * Retrieves the mapping for known data types to Search API's internal types.