diff --git a/README.md b/README.md
index b1aa36e80..9f86ab355 100644
--- a/README.md
+++ b/README.md
@@ -34,15 +34,18 @@ If the `semver-lock` CI check fails, regenerate locally and commit:
 just semver-lock
 ```
 
-If CI still rejects it (Foundry version mismatch), update your local Foundry first:
+If CI still rejects it because of a Foundry version mismatch, install and run the repository-pinned toolchain:
 
 ```bash
-foundryup
-just semver-lock
+mise install
+mise exec -- just semver-lock
 ```
 
+The Foundry version is pinned in `.mise.toml`. Use the pinned version when regenerating lock files and snapshots so local output matches CI.
+
 ### setup and testing
 
-- If you don't have foundry installed, run `just install-foundry`.
+- Install the pinned toolchain with `mise install`.
+- If you do not use mise, run `just install-foundry` and verify the installed version matches `.mise.toml`.
 - `just deps`
 - Test contracts: `just test`