diff --git a/src/avalanche/test/proof_tests.cpp b/src/avalanche/test/proof_tests.cpp
--- a/src/avalanche/test/proof_tests.cpp
+++ b/src/avalanche/test/proof_tests.cpp
@@ -432,11 +432,14 @@
         }
     };
 
+    gArgs.ForceSetArg("-legacyavaproof", "1");
+    BOOST_CHECK(Proof::useLegacy(gArgs));
     checkCases(legacyFormatTestCases);
 
     gArgs.ForceSetArg("-legacyavaproof", "0");
     BOOST_CHECK(!Proof::useLegacy(gArgs));
     checkCases(regularFormatTestCases);
+
     gArgs.ClearForcedArg("-legacyavaproof");
 }