diff --git a/MD_STD_IN.php b/MD_STD_IN.php
index ccc2e3a..e0ffdd5 100644
--- a/MD_STD_IN.php
+++ b/MD_STD_IN.php
@@ -47,7 +47,9 @@ class MD_STD_IN {
 
         $output = \filter_var($input,
             FILTER_SANITIZE_STRING,
-            FILTER_FLAG_NO_ENCODE_QUOTES) ?: "";
+            FILTER_FLAG_NO_ENCODE_QUOTES);
+
+        if ($output === false) return "";
 
         return trim($output);