diff --git a/doc/release-notes.md b/doc/release-notes.md
index 58994a683..0463cb8a6 100644
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -65,6 +65,8 @@ contain invalid parameters.
 
 The first boolean argument to `getaddednodeinfo` has been removed. This is an incompatible change.
 
+Call "getmininginfo" loses the "testnet" field in favor of the more generic "chain" (which has been present for years).
+
 ### Configuration and command-line options
 
 ### Block and transaction handling
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 727957085..5850016ae 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -133,7 +133,6 @@ public:
         fDefaultConsistencyChecks = false;
         fRequireStandard = true;
         fMineBlocksOnDemand = false;
-        fTestnetToBeDeprecatedFieldRPC = false;
 
         checkpointData = (CCheckpointData) {
             boost::assign::map_list_of
@@ -224,7 +223,6 @@ public:
         fDefaultConsistencyChecks = false;
         fRequireStandard = false;
         fMineBlocksOnDemand = false;
-        fTestnetToBeDeprecatedFieldRPC = true;
 
         checkpointData = (CCheckpointData) {
             boost::assign::map_list_of
@@ -286,7 +284,6 @@ public:
         fDefaultConsistencyChecks = true;
         fRequireStandard = false;
         fMineBlocksOnDemand = true;
-        fTestnetToBeDeprecatedFieldRPC = false;
 
         checkpointData = (CCheckpointData){
             boost::assign::map_list_of
diff --git a/src/chainparams.h b/src/chainparams.h
index 0c3820b7c..633fbd512 100644
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -67,8 +67,6 @@ public:
     uint64_t PruneAfterHeight() const { return nPruneAfterHeight; }
     /** Make miner stop after a block is found. In RPC, don't return until nGenProcLimit blocks are generated */
     bool MineBlocksOnDemand() const { return fMineBlocksOnDemand; }
-    /** In the future use NetworkIDString() for RPC fields */
-    bool TestnetToBeDeprecatedFieldRPC() const { return fTestnetToBeDeprecatedFieldRPC; }
     /** Return the BIP70 network string (main, test or regtest) */
     std::string NetworkIDString() const { return strNetworkID; }
     const std::vector<CDNSSeedData>& DNSSeeds() const { return vSeeds; }
@@ -91,7 +89,6 @@ protected:
     bool fDefaultConsistencyChecks;
     bool fRequireStandard;
     bool fMineBlocksOnDemand;
-    bool fTestnetToBeDeprecatedFieldRPC;
     CCheckpointData checkpointData;
 };
 
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 6b13aa5ba..fa64ce8fa 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -230,7 +230,6 @@ UniValue getmininginfo(const UniValue& params, bool fHelp)
             "  \"errors\": \"...\"            (string) Current errors\n"
             "  \"networkhashps\": nnn,      (numeric) The network hashes per second\n"
             "  \"pooledtx\": n              (numeric) The size of the mem pool\n"
-            "  \"testnet\": true|false      (boolean) If using testnet or not\n"
             "  \"chain\": \"xxxx\",           (string) current network name as defined in BIP70 (main, test, regtest)\n"
             "}\n"
             "\nExamples:\n"
@@ -250,7 +249,6 @@ UniValue getmininginfo(const UniValue& params, bool fHelp)
     obj.push_back(Pair("errors",           GetWarnings("statusbar")));
     obj.push_back(Pair("networkhashps",    getnetworkhashps(params, false)));
     obj.push_back(Pair("pooledtx",         (uint64_t)mempool.size()));
-    obj.push_back(Pair("testnet",          Params().TestnetToBeDeprecatedFieldRPC()));
     obj.push_back(Pair("chain",            Params().NetworkIDString()));
     return obj;
 }
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index f0b7e0a07..6bbb3925d 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -93,7 +93,7 @@ UniValue getinfo(const UniValue& params, bool fHelp)
         obj.push_back(Pair("connections",   (int)g_connman->GetNodeCount(CConnman::CONNECTIONS_ALL)));
     obj.push_back(Pair("proxy",         (proxy.IsValid() ? proxy.proxy.ToStringIPPort() : string())));
     obj.push_back(Pair("difficulty",    (double)GetDifficulty()));
-    obj.push_back(Pair("testnet",       Params().TestnetToBeDeprecatedFieldRPC()));
+    obj.push_back(Pair("testnet",       Params().NetworkIDString() == CBaseChainParams::TESTNET));
 #ifdef ENABLE_WALLET
     if (pwalletMain) {
         obj.push_back(Pair("keypoololdest", pwalletMain->GetOldestKeyPoolTime()));