diff --git a/.styleci.yml b/.styleci.yml
index 1caa7b894..6c7698f92 100644
--- a/.styleci.yml
+++ b/.styleci.yml
@@ -27,6 +27,7 @@ enabled:
   - no_unreachable_default_argument_value
   - no_unused_imports
   - no_whitespace_before_comma_in_array
+  - nullable_type_declarations
   - ordered_imports
   - phpdoc_align
   - phpdoc_indent