Code inspection: Nullability conflicts with annotations in hierarchy

This inspection reports a conflict between nullable reference type syntax and JetBrains nullability annotations inherited from the member hierarchy. That means the ? or non-nullable type in the current declaration does not agree with the nullability annotations expected by related base or overridden members.

Example

                using JetBrains.Annotations;
                class Base
                {
                    [CanBeNull]
                    public virtual string GetText() => null;
                }
                class Derived : Base
                {
                    public override string GetText() => "";
                }
            

                using JetBrains.Annotations;
                class Base
                {
                    [CanBeNull]
                    public virtual string GetText() => null;
                }
                class Derived : Base
                {
                    public override string? GetText() => "";
                }
            

Quick-fix

The quick-fix changes the type nullability to match the annotations used in the hierarchy.

01 April 2026