diff --git a/classes/Config.php b/classes/Config.php
index c413317be..6e16f269b 100644
--- a/classes/Config.php
+++ b/classes/Config.php
@@ -275,6 +275,13 @@ class Config {
 			if (isset(self::_DEFAULTS[$const])) {
 				$override = getenv(self::_ENVVAR_PREFIX . $const);
 
+				// cleanup original env var after importing (unless it's a background process)
+				if (php_sapi_name() != "cli") {
+					putenv(self::_ENVVAR_PREFIX . $const . '=');
+					unset($_ENV[self::_ENVVAR_PREFIX . $const]);
+					unset($_SERVER[self::_ENVVAR_PREFIX . $const]);
+				}
+
 				list ($defval, $deftype) = self::_DEFAULTS[$const];
 
 				$this->params[$cvalue] = [ self::cast_to($override !== false ? $override : $defval, $deftype), $deftype ];
@@ -433,6 +440,13 @@ class Config {
 	private function _add(string $param, string $default, int $type_hint): void {
 		$override = getenv(self::_ENVVAR_PREFIX . $param);
 
+		// cleanup original env var after importing (unless it's a background process)
+		if (php_sapi_name() != "cli") {
+			putenv(self::_ENVVAR_PREFIX . $param . '=');
+			unset($_ENV[self::_ENVVAR_PREFIX . $param]);
+			unset($_SERVER[self::_ENVVAR_PREFIX . $param]);
+		}
+
 		$this->params[$param] = [ self::cast_to($override !== false ? $override : $default, $type_hint), $type_hint ];
 	}