diff --git a/src/portfolio_optimiser/reference_domain.py b/src/portfolio_optimiser/reference_domain.py
index ba496f5..f156f8e 100644
--- a/src/portfolio_optimiser/reference_domain.py
+++ b/src/portfolio_optimiser/reference_domain.py
@@ -77,7 +77,7 @@ def load_reference_projects() -> tuple[Project, ...]:
                 )
                 for c in p["cost_items"]
             ),
-            docs_dir=str(files("portfolio_optimiser").joinpath("data", p["docs_dir"])),
+            docs_dir=str(files("portfolio_optimiser").joinpath(f"data/{p['docs_dir']}")),
             verdict_input=p["verdict_input"],
         )
         for p in raw["projects"]