PHP error guide

Passing null to non-nullable internal parameter is deprecated: meaning and fix

notice deprecated Affects: PHP 8.1+ Last verified:

Error summary

Resolve null to a valid value or reject it before the internal call. Null is passed to an internal function parameter declared non-nullable.

What it means

Resolve null to a valid value or reject it before the internal call. Null is passed to an internal function parameter declared non-nullable.

What the error means

This message means that null is passed to an internal function parameter declared non-nullable. The exact signature distinguishes passing null to non-nullable internal parameter is deprecated from a generic application failure.

Why PHP produces it

The engine or service reports “Passing null to non-nullable internal parameter is deprecated” because its required precondition was not met. Resolve null to a valid value or reject it before the internal call.

PHP version notes

The passing null to non-nullable internal parameter is deprecated wording here is based on PHP 8.1+; punctuation and exception class names can differ on older branches or vendor builds.

Most common causes

  • The immediate input or configuration reaches the specific condition: null is passed to an internal function parameter declared non-nullable
  • The code path assumes the prerequisite for passing null to non-nullable internal parameter is deprecated has already been satisfied.
  • For passing null to non-nullable internal parameter is deprecated, development and production differ in version, extension, permissions, paths, or service configuration.
  • An earlier operation returned an unchecked value that is consumed by the line reporting passing null to non-nullable internal parameter is deprecated.

Minimal examples

BAD — reproduces the problem

php 
echo strlen($name);

FIXED — safer pattern

php 
echo strlen($name ?? "");

Step-by-step diagnosis

  1. Copy the complete “Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated” text and retain the first application stack frame.
  2. Reproduce passing null to non-nullable internal parameter is deprecated in the same SAPI and environment listed for this page.
  3. Before changing passing null to non-nullable internal parameter is deprecated, inspect the preceding value or directive and verify its type, path, version, and permissions.
  4. Apply the narrow correction—resolve null to a valid value or reject it before the internal call—then repeat the original request once.

Fixes

Correct the failing prerequisite

Resolve null to a valid value or reject it before the internal call

php 
echo strlen($name ?? "");

Fail explicitly at the boundary

Validate the condition before the operation that emits passing null to non-nullable internal parameter is deprecated, and log a safe diagnostic without credentials or full production paths.

Common mistakes when fixing it

  • Suppressing passing null to non-nullable internal parameter is deprecated instead of correcting its upstream condition.
  • Testing passing null to non-nullable internal parameter is deprecated only with the CLI binary when the failing request runs under FPM or Apache.
  • Changing a global setting for passing null to non-nullable internal parameter is deprecated before confirming the site-specific effective configuration.

How to prevent it

  • Add a focused test that exercises the boundary responsible for passing null to non-nullable internal parameter is deprecated.
  • Keep runtime versions, extensions, configuration, and deploy artifacts affecting passing null to non-nullable internal parameter is deprecated reproducible.
  • Validate external data and service return values before they can trigger passing null to non-nullable internal parameter is deprecated.

Modernization guides

Web server / environment notes

cli, fpm, apache. The failure occurs where null is passed to an internal function parameter declared non-nullable

Tags: cli,fpm,apache

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