diff --git a/src/command/build/runner.rs b/src/command/build/runner.rs
index b9fe1b7..9b9b8c3 100644
--- a/src/command/build/runner.rs
+++ b/src/command/build/runner.rs
@@ -66,13 +66,27 @@ async fn filter_to_highest_folders_containing_org_files(
     entry: &DirEntry,
 ) -> Result<WalkAction, CustomError> {
     let file_type = entry.file_type().await?;
+    if !file_type.is_dir() {
+        return Ok(WalkAction::Halt);
+    }
     let mut entries = tokio::fs::read_dir(entry.path()).await?;
-
-    todo!()
+    while let Some(entry) = entries.next_entry().await? {
+        let entry_type = entry.file_type().await?;
+        if !entry_type.is_file() {
+            continue;
+        }
+        match entry.path().extension().and_then(OsStr::to_str) {
+            Some("org") => {
+                return Ok(WalkAction::HaltAndCapture);
+            }
+            _ => {}
+        }
+    }
+    Ok(WalkAction::Recurse)
 }
 
 async fn get_post_directories(config: &Config) -> Result<Vec<PathBuf>, CustomError> {
-    walk_fs(
+    let top_level_org_folders = walk_fs(
         config.get_posts_directory(),
         filter_to_highest_folders_containing_org_files,
     )