diff --git a/tests/diff_ghw.rs b/tests/diff_ghw_vs_fst.rs
similarity index 100%
rename from tests/diff_ghw.rs
rename to tests/diff_ghw_vs_fst.rs
diff --git a/tests/ghw_diff.rs b/tests/ghw_diff.rs
new file mode 100644
index 0000000..49b205b
--- /dev/null
+++ b/tests/ghw_diff.rs
@@ -0,0 +1,26 @@
+// Copyright 2024 The Regents of the University of California
+// released under BSD 3-Clause License
+// author: Kevin Laeufer <laeufer@berkeley.edu>
+//
+// comparing the output of the ghwdump tool and wellen
+
+
+use std::sync::Once;
+
+static COMPILE_GHW_DUMP: Once = Once::new();
+
+
+fn compile_ghwdump() {
+
+}
+
+fn run_ghwdump(filename: &str) {
+    // make sure ghwdump is compiled
+    COMPILE_GHW_DUMP.call_once(|| compile_ghwdump());
+}
+
+
+#[test]
+fn diff_ghdl_oscar_test() {
+    run_ghwdump("inputs/ghdl/oscar/test.ghw");
+}