A function is declared in a file that has strict_types=1, but a non-strict file calls it …

A function is declared in a file that has strict_types=1, but a non-strict file calls it with numeric strings for int parameters. Which rule applies?

1. The caller's coercive rule applies, so the strings may be converted before entry.
2. The declaration file forces strict arguments for every caller.
3. strict_types affects return values only.
4. PHP ignores scalar declarations across files.