diff --git a/pipeline/src/test_util.rs b/pipeline/src/test_util.rs
index d89b559d7..fc34b9112 100644
--- a/pipeline/src/test_util.rs
+++ b/pipeline/src/test_util.rs
@@ -200,7 +200,7 @@ pub fn test_halo2_with_backend_variant(
 #[cfg(not(feature = "halo2"))]
 pub fn test_halo2_with_backend_variant(
     _pipeline: Pipeline<Bn254Field>,
-    backend_variant: BackendVariant,
+    _backend_variant: BackendVariant,
 ) {
 }