diff --git a/lit.cfg b/lit.cfg
index d8be816dcd..77f9732bd6 100644
--- a/lit.cfg
+++ b/lit.cfg
@@ -53,5 +53,5 @@ if lit_config.params.get("profile") == "hpmcount":
     config.test_modules += ["hpmcount"]
 
 config.substitutions += [
-    ("%b", os.path.join(config.test_exec_root, "tools")),
+    ("%b", os.path.join(config.test_source_root, "tools")),
 ]