diff --git a/src/config/config.cpp b/src/config/config.cpp
index c283d203e..6602c37e5 100644
--- a/src/config/config.cpp
+++ b/src/config/config.cpp
@@ -1,4 +1,5 @@
 #include <string>
+#include <fstream>
 #include <nlohmann/json.hpp>
 #include "definitions.hpp"
 #include "config.hpp"
@@ -263,7 +264,13 @@ void Config::load(json &config)
     finalVerifier = configPath + "/final/final.verifier.dat";
     finalVerkey = configPath + "/final/final.fflonk.verkey.json";
     finalStarkZkey = configPath + "/final/final.fflonk.zkey";
-
+    // check if file exists
+    ifstream f;
+    f.open(finalVerkey);
+    if (f.fail()) {
+        finalVerkey = configPath + "/final/final.verkey.json";
+        finalStarkZkey = configPath + "/final/final.g16.0001.zkey";
+    }
 
     if (config.contains("rom") && config["rom"].is_string())
         rom = config["rom"];
diff --git a/src/prover/prover.cpp b/src/prover/prover.cpp
index 45ada1f5f..7f8878af7 100644
--- a/src/prover/prover.cpp
+++ b/src/prover/prover.cpp
@@ -113,8 +113,10 @@ Prover::Prover(Goldilocks &fr,
                 cout << "Prover::genBatchProof() successfully allocated " << polsSize << " bytes" << endl;
             }
 
-            prover = new Fflonk::FflonkProver<AltBn128::Engine>(AltBn128::Engine::engine, pAddress, polsSize);
-            prover->setZkey(zkey.get());
+            if (Zkey::FFLONK_PROTOCOL_ID == protocolId) {
+                prover = new Fflonk::FflonkProver<AltBn128::Engine>(AltBn128::Engine::engine, pAddress, polsSize);
+                prover->setZkey(zkey.get());
+            }
 
             StarkInfo _starkInfoRecursiveF(config, config.recursivefStarkInfo);
             pAddressStarksRecursiveF = (void *)malloc(_starkInfoRecursiveF.mapTotalN * sizeof(Goldilocks::Element));
@@ -142,8 +144,6 @@ Prover::~Prover()
         BinFileUtils::BinFile *pZkey = zkey.release();
         ZKeyUtils::Header *pZkeyHeader = zkeyHeader.release();
 
-        assert(groth16Prover.get() == nullptr);
-        assert(groth16Prover == nullptr);
         assert(zkey.get() == nullptr);
         assert(zkey == nullptr);
         assert(zkeyHeader.get() == nullptr);
@@ -168,7 +168,8 @@ Prover::~Prover()
         }
         free(pAddressStarksRecursiveF);
 
-        delete prover;
+        if (prover != NULL)
+            delete prover;
 
         delete starkZkevm;
         delete starksC12a;