diff --git a/classes/config.php b/classes/config.php
index cd10c0158..3e643b2d0 100644
--- a/classes/config.php
+++ b/classes/config.php
@@ -139,7 +139,7 @@ class Config {
 
 				list ($defval, $deftype) = $this::_DEFAULTS[$const];
 
-				$this->params[$cvalue] = [ self::cast_to(!empty($override) ? $override : $defval, $deftype), $deftype ];
+				$this->params[$cvalue] = [ self::cast_to($override !== false ? $override : $defval, $deftype), $deftype ];
 			}
 		}
 	}
@@ -264,7 +264,7 @@ class Config {
 	private function _add(string $param, string $default, int $type_hint) {
 		$override = getenv($this::_ENVVAR_PREFIX . $param);
 
-		$this->params[$param] = [ self::cast_to(!empty($override) ? $override : $default, $type_hint), $type_hint ];
+		$this->params[$param] = [ self::cast_to($override !== false ? $override : $default, $type_hint), $type_hint ];
 	}
 
 	static function add(string $param, string $default, int $type_hint = Config::T_STRING) {