diff --git a/google_webfont_loader_api.module b/google_webfont_loader_api.module
index 33edcb2..a0bc8fc 100755
--- a/google_webfont_loader_api.module
+++ b/google_webfont_loader_api.module
@@ -152,6 +152,17 @@ function _google_webfont_loader_api_load_js_from_fontinfo($font_info, $filepath)
         }
       }
     }
+    // If specified, load and use custom test strings.
+    if ($key == "custom_families" && is_array($font_info['custom_testStrings'])) {
+      foreach ($font_info['custom_testStrings'] as $string) {
+        /* testString should be added to info file escaped like:
+          custom_testStrings[] = '\\uE001\\uE002\\uE838' */
+        $str = preg_replace_callback('/\\\\u([0-9a-fA-F]{4})/', function ($match) {
+          return mb_convert_encoding(pack('H*', $match[1]), 'UTF-8', 'UTF-16BE');
+        }, $string);
+        $loader_js['custom']['testStrings'][$info[0]] = $str;
+      }
+    }
   }
   return google_webfont_loader_api_add_js($loader_js);
 }