diff --git a/class.krumo.php b/class.krumo.php
index 6ac1550..c83a6f7 100644
--- a/class.krumo.php
+++ b/class.krumo.php
@@ -499,8 +499,9 @@ public static function dump($data, $second = '')
         $_ = debug_backtrace();
         while ($d = array_pop($_)) {
             $callback = static::$lineNumberTestCallback;
-            $function = strToLower($d['function']);
-            if (in_array($function, array("krumo","k","kd")) || (strToLower(@$d['class']) == 'krumo') || (is_callable($callback) && call_user_func($callback, $d))) {
+            $class    = strtolower($d['class'] ?? '');
+            $function = strtolower($d['function'] ?? '');
+            if (in_array($function, array('krumo','k','kd')) || $class == 'krumo' || (is_callable($callback) && call_user_func($callback, $d))) {
                 break;
             }
         }
@@ -1607,7 +1608,7 @@ private static function cli_dump() {
         }
 
         foreach ($args as $i) {
-            $out = var_export($i);
+            $out = var_export($i) ?? '';
             print trim($out);
 
             if (sizeof($args) >= 1) {
diff --git a/composer.json b/composer.json
index 5abac28..3781d61 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
     }
     ],
     "require": {
-        "php": ">=5.2.17"
+        "php": ">=7.0"
     },
     "require-dev": {
         "fabpot/php-cs-fixer": "dev-master",