diff --git a/provekit/verifier/src/whir_r1cs.rs b/provekit/verifier/src/whir_r1cs.rs
index d3a148b9a..a02356024 100644
--- a/provekit/verifier/src/whir_r1cs.rs
+++ b/provekit/verifier/src/whir_r1cs.rs
@@ -209,7 +209,9 @@ impl WhirR1CSVerifier for WhirR1CSScheme {
             "last sumcheck value does not match"
         );
 
-        Ok(())
+        arthur
+            .check_eof()
+            .map_err(|_| anyhow::anyhow!("Proof contains unparsed trailing bytes"))
     }
 }