diff --git a/josh-core/src/filter/mod.rs b/josh-core/src/filter/mod.rs
index bb6e2bada..36bb6132b 100644
--- a/josh-core/src/filter/mod.rs
+++ b/josh-core/src/filter/mod.rs
@@ -1543,12 +1543,14 @@ fn per_rev_filter(
             )?;
 
             let parent = transaction.repo().find_commit(parent)?;
-            let parent = parent.tree()?;
 
-            let pin_subtract = pin_subtract.tree();
-            let pin_overlay = tree::transpose(transaction, pin_subtract, &parent)?;
+            let pin_overlay = tree::populate(
+                transaction,
+                tree::pathstree("", pin_subtract.tree.id(), transaction)?.id(),
+                parent.tree_id(),
+            )?;
 
-            Some((pin_subtract.id(), pin_overlay.id()))
+            Some((pin_subtract.tree.id(), pin_overlay))
         } else {
             None
         }
diff --git a/josh-core/src/filter/tree.rs b/josh-core/src/filter/tree.rs
index 49e7b1a8a..0fc1d8fd0 100644
--- a/josh-core/src/filter/tree.rs
+++ b/josh-core/src/filter/tree.rs
@@ -1,5 +1,4 @@
 use super::*;
-use std::path::PathBuf;
 
 use crate::cache::TransactionContext;
 use crate::cache_stack::CacheStack;
@@ -890,7 +889,7 @@ pub fn repopulated_tree(
     populate(transaction, ipaths.id(), partial_tree.id())
 }
 
-fn populate(
+pub fn populate(
     transaction: &cache::Transaction,
     paths: git2::Oid,
     content: git2::Oid,
@@ -1002,41 +1001,6 @@ pub fn get_blob(repo: &git2::Repository, tree: &git2::Tree, path: &Path) -> Stri
     content.to_owned()
 }
 
-/// Compose a new tree by taking paths out of `paths`,
-/// and actual blobs out of `blobs`.
-pub fn transpose<'a>(
-    transaction: &'a cache::Transaction,
-    paths: &'a git2::Tree,
-    blobs: &'a git2::Tree,
-) -> JoshResult<git2::Tree<'a>> {
-    use git2::build::TreeUpdateBuilder;
-    use git2::{TreeWalkMode, TreeWalkResult};
-
-    let mut builder = TreeUpdateBuilder::new();
-
-    paths.walk(TreeWalkMode::PostOrder, |path, entry| {
-        let path = PathBuf::from(path).join(entry.name().unwrap_or(""));
-
-        let entry = match blobs.get_path(&path) {
-            Ok(entry) => entry,
-            Err(e) if e.code() == git2::ErrorCode::NotFound => return TreeWalkResult::Ok,
-            Err(_) => return TreeWalkResult::Abort,
-        };
-
-        if entry.kind() != Some(git2::ObjectType::Blob) {
-            return TreeWalkResult::Ok;
-        }
-
-        builder.upsert(path, entry.id(), git2::FileMode::Blob);
-        TreeWalkResult::Ok
-    })?;
-
-    let repo = transaction.repo();
-    let tree = builder.create_updated(repo, &empty(repo))?;
-
-    Ok(repo.find_tree(tree)?)
-}
-
 pub fn empty_id() -> git2::Oid {
     git2::Oid::from_str("4b825dc642cb6eb9a060e54bf8d69288fbee4904").unwrap()
 }