diff --git a/stubs/CoreGenericFunctions.phpstub b/stubs/CoreGenericFunctions.phpstub
index b49b72315..ea26ca5c8 100644
--- a/stubs/CoreGenericFunctions.phpstub
+++ b/stubs/CoreGenericFunctions.phpstub
@@ -1306,5 +1306,6 @@ function is_a($object_or_class, string $class, $allow_string = false): bool{}
  * @template T of array|string
  * @param T $string
  * @return (T is array<int, string> ? array<int, string> : T is array ? array : string|false)
+ * @psalm-ignore-falsable-return
  */
 function mb_convert_encoding(array|string $string, string $to_encoding, array|string|null $from_encoding = null): array|string|false{}