Some contract clauses make declarative statements about what is or is not permitted. For example: "This Agreement may be amended only in writing."

Conceivably, though, one party might later claim that the parties had agreed orally to amend the contract; that the oral agreement was valid under the Statute of Frauds; and therefore the oral amendment must be given precedence over the prior written-amendments-only clause.

One way to try to avoid this problem might be to couple a declarative statement of this kind with a covenant (that is, a promise) not to assert otherwise.

In the example above, a party asserting that the contract had been amended orally would arguably be in breach of contract just for having made that assertion. The obvious remedy would be to give effect to the written-amendments-only clause.

This may be more a theoretical concern than a real one, but the author remembers reading a case report in which something like this happened. The plaintiff claimed fraud in the inducement, but the contract's integration clause said that neither party was relying on extraneous representations. The court granted summary judgment for the defendant, saying that the plaintiff would have been in breach of contract if it had relied on the alleged fraudulent inducement despite its representation of no reliance.