diff --git a/tools/ci_setup.ml b/tools/ci_setup.ml
index 9cf69d3dbe..185d5a5126 100644
--- a/tools/ci_setup.ml
+++ b/tools/ci_setup.ml
@@ -261,7 +261,7 @@ let () =
       let p = if Sys.win32 then "patch --binary" else "patch" in
       let ch =
         Unix.open_process_out
-          (Printf.sprintf "cd %s/lib/%s && %s -p 1 --" jane_root p dir)
+          (Printf.sprintf "cd %s/lib/%s && %s -p 1 --" jane_root dir p)
       in
       let patch =
         if Sys.win32