diff --git a/lib/src/commit_builder.rs b/lib/src/commit_builder.rs
index 67c50e48a..7a6ea1d2b 100644
--- a/lib/src/commit_builder.rs
+++ b/lib/src/commit_builder.rs
@@ -32,7 +32,8 @@ pub struct CommitBuilder<'repo> {
 }
 
 impl CommitBuilder<'_> {
-    pub fn for_new_commit<'repo>(
+    // Use MutRepo::new_commit() instead
+    pub(crate) fn for_new_commit<'repo>(
         mut_repo: &'repo mut MutableRepo,
         settings: &UserSettings,
         parents: Vec<CommitId>,
@@ -61,7 +62,8 @@ impl CommitBuilder<'_> {
         }
     }
 
-    pub fn for_rewrite_from<'repo>(
+    // Use MutRepo::rewrite_commit() instead
+    pub(crate) fn for_rewrite_from<'repo>(
         mut_repo: &'repo mut MutableRepo,
         settings: &UserSettings,
         predecessor: &Commit,
diff --git a/lib/src/repo.rs b/lib/src/repo.rs
index dbc3f5193..bfe88867d 100644
--- a/lib/src/repo.rs
+++ b/lib/src/repo.rs
@@ -796,6 +796,8 @@ impl MutableRepo {
         predecessor: &Commit,
     ) -> CommitBuilder {
         CommitBuilder::for_rewrite_from(self, settings, predecessor)
+        // CommitBuilder::write will record the rewrite in
+        // `self.rewritten_commits`
     }
 
     pub fn write_commit(