diff --git a/doc/builders/fetchers.chapter.md b/doc/builders/fetchers.chapter.md
index e52d01cbb8e..ce6c214259a 100644
--- a/doc/builders/fetchers.chapter.md
+++ b/doc/builders/fetchers.chapter.md
@@ -32,7 +32,9 @@ fetchurl {
 };
 ```
 
-Hash mismatches generate an error message containing the correct sha256.
+Use the resulting error message to determine the correct hash.
+
+<error message here>
 
 A similar problem arises while testing changes to a fetcher's implementation. If the output of the derivation already exists in the Nix store, test failures can go undetected. The [`invalidateFetcherByDrvHash`](#tester-invalidateFetcherByDrvHash) function helps prevent reusing cached derivations.