diff --git a/src/stdune/path.ml b/src/stdune/path.ml
index 06217960..c806c749 100644
--- a/src/stdune/path.ml
+++ b/src/stdune/path.ml
@@ -511,7 +511,7 @@ end = struct
     | _               , In_source_tree _ -> Gt
     | In_build_dir x  , In_build_dir y   -> Local.compare x y
 
-  let equal = (=)
+  let equal (x : t) (y : t) = x = y
   let hash = Hashtbl.hash
 
   let in_build_dir s = In_build_dir s