When measures are taken which, if taken previously, would have made an event less likely to occur, evidence of the subsequent measures is not admissible to prove a defect in a product, negligence, or culpable conduct in connection with the event. In a product liability action brought under any theory or doctrine, if the feasibility of a design change or change in warnings is not controverted, then a subsequent design change or change in warnings shall not be admissible into evidence. This rule does not require the exclusion of evidence of subsequent measures when offered for another purpose such as proving ownership, control, or impeachment.
2-2105.Changes in design or warning; inadmissibility.
Article II. Civil Practice · Part 21. Product Liability · Last amended 1995 · Last verified July 20, 2026
In one sentenceSection 2-2105 keeps evidence of a later design or warning change out of a product liability case when the feasibility of that change isn't disputed, though the evidence may still come in for another purpose like proving ownership, control, or impeachment.
Full Text of 735 ILCS 5/2-2105
Plain-English Summary
Section 2-2105 starts with a general rule: when a measure taken after an event would, if taken before, have made the event less likely, evidence of that subsequent measure isn't admissible to prove a defect in a product, negligence, or culpable conduct connected with the event. It then applies a specific version of that rule to product liability actions: if the feasibility of a design change or a change in warnings isn't controverted, a subsequent design change or warning change isn't admissible into evidence.
The effect is that a manufacturer's decision to improve a product or its warnings after the fact doesn't, by itself, become evidence that the earlier version was defective, at least where nobody disputes that the change was feasible to make.
The section carves out a clear exception: it doesn't require excluding evidence of a subsequent measure when it's offered for another purpose, such as proving ownership, control, or impeachment. The exclusion is tied to the specific purpose of proving a defect or fault, not to the evidence generally.
Frequently Asked Questions
Can a manufacturer's later design change be used against it in a lawsuit?
Not to prove a defect, negligence, or culpable conduct, when the feasibility of the change isn't disputed. Section 2-2105 excludes that evidence for that purpose.
What must be true for a subsequent design change to be excluded from evidence?
The feasibility of the design change or warning change has to be uncontroverted. If feasibility is disputed, this specific exclusion doesn't apply the same way.
Does this rule ever allow evidence of a later warning or design change?
Yes, when the evidence is offered for a purpose other than proving a defect, negligence, or culpable conduct — the section names proving ownership, control, or impeachment as examples that remain admissible.
Does this section only apply to product liability actions?
The first sentence states a general subsequent-measures rule for any event where a later measure would have made it less likely. The second sentence then applies a design-and-warning-specific version of that rule to product liability actions brought under any theory or doctrine.
How does this rule affect a manufacturer's decision to improve a product after it's sold?
It limits how that later change can be used in litigation: where feasibility isn't disputed, the change itself isn't admissible to show the earlier design or warning was defective, though it can still be used for other evidentiary purposes.
Amendment History
(Source: P.A. 89-7, eff. 3-9-95.)
Source & verification. Section text and amendment history are
reproduced verbatim from the Illinois Compiled Statutes, published by the
Illinois Compiled Statutes, Illinois General Assembly / Legislative Reference Bureau. Last verified July 20, 2026.
· Official source
Also known as: subsequent remedial measures illinois product liabilitydesign change evidence inadmissible illinoiswarning change evidence product liability illinois