diff --git a/src/net.h b/src/net.h
--- a/src/net.h
+++ b/src/net.h
@@ -24,6 +24,7 @@
 #include <sync.h>
 #include <threadinterrupt.h>
 #include <uint256.h>
+#include <util/check.h>
 #include <validation.h> // For cs_main
 
 #include <atomic>
@@ -1114,6 +1115,7 @@
                          bool &complete);
 
     void SetCommonVersion(int greatest_common_version) {
+        Assume(m_greatest_common_version == INIT_PROTO_VERSION);
         m_greatest_common_version = greatest_common_version;
     }
     int GetCommonVersion() const { return m_greatest_common_version; }
diff --git a/src/test/fuzz/net.cpp b/src/test/fuzz/net.cpp
--- a/src/test/fuzz/net.cpp
+++ b/src/test/fuzz/net.cpp
@@ -55,8 +55,9 @@
                    {ConnectionType::INBOUND, ConnectionType::OUTBOUND,
                     ConnectionType::MANUAL, ConnectionType::FEELER,
                     ConnectionType::BLOCK_RELAY, ConnectionType::ADDR_FETCH})};
+    node.SetCommonVersion(fuzzed_data_provider.ConsumeIntegral<int>());
     while (fuzzed_data_provider.ConsumeBool()) {
-        switch (fuzzed_data_provider.ConsumeIntegralInRange<int>(0, 11)) {
+        switch (fuzzed_data_provider.ConsumeIntegralInRange<int>(0, 10)) {
             case 0: {
                 node.CloseSocketDisconnect();
                 break;
@@ -67,11 +68,6 @@
                 break;
             }
             case 2: {
-                node.SetCommonVersion(
-                    fuzzed_data_provider.ConsumeIntegral<int>());
-                break;
-            }
-            case 3: {
                 const std::vector<bool> asmap =
                     ConsumeRandomLengthIntegralVector<bool>(
                         fuzzed_data_provider, 128);
@@ -82,18 +78,18 @@
                 node.copyStats(stats, asmap);
                 break;
             }
-            case 4: {
+            case 3: {
                 const CNode *add_ref_node = node.AddRef();
                 assert(add_ref_node == &node);
                 break;
             }
-            case 5: {
+            case 4: {
                 if (node.GetRefCount() > 0) {
                     node.Release();
                 }
                 break;
             }
-            case 6: {
+            case 5: {
                 if (node.m_addr_known == nullptr) {
                     break;
                 }
@@ -105,7 +101,7 @@
                 node.AddAddressKnown(*addr_opt);
                 break;
             }
-            case 7: {
+            case 6: {
                 if (node.m_addr_known == nullptr) {
                     break;
                 }
@@ -119,7 +115,7 @@
                 node.PushAddress(*addr_opt, fast_random_context);
                 break;
             }
-            case 8: {
+            case 7: {
                 const std::optional<CInv> inv_opt =
                     ConsumeDeserializable<CInv>(fuzzed_data_provider);
                 if (!inv_opt) {
@@ -129,12 +125,12 @@
                 node.AddKnownTx(txid);
                 break;
             }
-            case 9: {
+            case 8: {
                 const TxId &txid = TxId(ConsumeUInt256(fuzzed_data_provider));
                 node.PushTxInventory(txid);
                 break;
             }
-            case 10: {
+            case 9: {
                 const std::optional<CService> service_opt =
                     ConsumeDeserializable<CService>(fuzzed_data_provider);
                 if (!service_opt) {
@@ -143,7 +139,7 @@
                 node.SetAddrLocal(*service_opt);
                 break;
             }
-            case 11: {
+            case 10: {
                 const std::vector<uint8_t> b =
                     ConsumeRandomLengthByteVector(fuzzed_data_provider);
                 bool complete;