Fix

Author: ondrejmirtes

src/Type/TypeCombinator.php

@@ -1219,6 +1219,7 @@ public static function intersect(Type ...$types): Type
 					if (
 						$types[$i] instanceof ConstantArrayType
 						&& count($types[$i]->getKeyTypes()) === 1
+						&& $types[$i]->isOptionalKey(0)
 						&& $types[$j] instanceof NonEmptyArrayType
 					) {
 						$types[$i] = $types[$i]->makeOffsetRequired($types[$i]->getKeyTypes()[0]);
@@ -1230,6 +1231,7 @@ public static function intersect(Type ...$types): Type
 					if (
 						$types[$j] instanceof ConstantArrayType
 						&& count($types[$j]->getKeyTypes()) === 1
+						&& $types[$j]->isOptionalKey(0)
 						&& $types[$i] instanceof NonEmptyArrayType
 					) {
 						$types[$j] = $types[$j]->makeOffsetRequired($types[$j]->getKeyTypes()[0]);