diff --git a/src/v/migrations/feature_migrator.h b/src/v/migrations/feature_migrator.h
index 96e601976b5af..7acfec7ac698c 100644
--- a/src/v/migrations/feature_migrator.h
+++ b/src/v/migrations/feature_migrator.h
@@ -43,6 +43,9 @@ class feature_migrator {
      * If not overriding `start` and `do_migrate`, then implement
      * `do_mutate` to express the change that should be made to
      * the system during upgrade.
+     *
+     * `do_mutate` should be idempotent as it may be executed multiple times if
+     * there is a leader reelection while do_mutate is being executed.
      */
     virtual ss::future<> do_mutate() { return ss::now(); }
     ss::future<> do_migrate();