diff --git a/benches/repo.rs b/benches/repo.rs
index 6a41731..d9d1fd1 100644
--- a/benches/repo.rs
+++ b/benches/repo.rs
@@ -60,10 +60,12 @@ impl Repo {
     }
 }
 
+/// relative, because cargo runs benches from the package root: an absolute path baked in here
+/// would make builds of the same code from two checkouts lay their code out differently
 fn data_dir() -> PathBuf {
     std::env::var_os("HYDRANT_BENCH_DATA")
         .map(PathBuf::from)
-        .unwrap_or_else(|| PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("target/bench-data"))
+        .unwrap_or_else(|| PathBuf::from("target/bench-data"))
 }
 
 fn repos() -> &'static [Repo] {