diff --git a/resources/functions.php b/resources/functions.php
index 0030725532..ba8c73a3f7 100644
--- a/resources/functions.php
+++ b/resources/functions.php
@@ -33,7 +33,7 @@
 
 	if (!function_exists('check_float')) {
 		function check_float($string) {
-			$string = str_replace(",",".",$string);
+			$string = str_replace(",",".",$string ?? '');
 			return trim($string);
 		}
 	}