diff --git a/doc/release-notes.md b/doc/release-notes.md
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -5,6 +5,7 @@
   <https://download.bitcoinabc.org/0.22.5/>
 
 This release includes the following features and fixes:
+- The `-upgradewallet` command line flag has been replaced in favor of the `upgradewallet` RPC.
 
 Updated RPCs
 ------------
diff --git a/src/wallet/init.cpp b/src/wallet/init.cpp
--- a/src/wallet/init.cpp
+++ b/src/wallet/init.cpp
@@ -107,8 +107,6 @@
             "Spend unconfirmed change when sending transactions (default: %d)",
             DEFAULT_SPEND_ZEROCONF_CHANGE),
         ArgsManager::ALLOW_ANY, OptionsCategory::WALLET);
-    gArgs.AddArg("-upgradewallet", "Upgrade wallet to latest format on startup",
-                 ArgsManager::ALLOW_ANY, OptionsCategory::WALLET);
     gArgs.AddArg("-wallet=<path>",
                  "Specify wallet database path. Can be specified multiple "
                  "times to load multiple wallets. Path is interpreted relative "
@@ -217,14 +215,6 @@
         }
     }
 
-    if (is_multiwallet) {
-        if (gArgs.GetBoolArg("-upgradewallet", false)) {
-            return InitError(
-                strprintf("%s is only allowed with a single wallet file",
-                          "-upgradewallet"));
-        }
-    }
-
     if (gArgs.GetBoolArg("-sysperms", false)) {
         return InitError("-sysperms is not allowed in combination with enabled "
                          "wallet functionality");
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -3088,8 +3088,7 @@
         "Loads a wallet from a wallet file or directory."
         "\nNote that all wallet command-line options used when starting "
         "bitcoind will be"
-        "\napplied to the new wallet (eg -zapwallettxes, upgradewallet, "
-        "rescan, etc).\n",
+        "\napplied to the new wallet (eg -zapwallettxes, rescan, etc).\n",
         {
             {"filename", RPCArg::Type::STR, RPCArg::Optional::NO,
              "The wallet directory or .dat file."},
@@ -4534,8 +4533,8 @@
     if (!pwallet->CanSupportFeature(FEATURE_HD)) {
         throw JSONRPCError(
             RPC_WALLET_ERROR,
-            "Cannot set a HD seed on a non-HD wallet. Start with "
-            "-upgradewallet in order to upgrade a non-HD wallet to HD");
+            "Cannot set a HD seed on a non-HD wallet. Use the upgradewallet "
+            "RPC in order to upgrade a non-HD wallet to HD");
     }
 
     EnsureWalletIsUnlocked(pwallet);
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -4145,13 +4145,6 @@
         }
     }
 
-    if (gArgs.GetBoolArg("-upgradewallet", false)) {
-        if (!walletInstance->UpgradeWallet(gArgs.GetArg("-upgradewallet", 0),
-                                           error, warnings)) {
-            return nullptr;
-        }
-    }
-
     if (fFirstRun) {
         // Ensure this wallet.dat can only be opened by clients supporting
         // HD with chain split and expects no default key.
@@ -4488,8 +4481,8 @@
         max_version >= FEATURE_HD_SPLIT &&
         max_version < FEATURE_PRE_SPLIT_KEYPOOL) {
         error = _("Cannot upgrade a non HD split wallet without upgrading to "
-                  "support pre split keypool. Please use -upgradewallet=200300 "
-                  "or -upgradewallet with no version specified.");
+                  "support pre split keypool. Please use version 200300 or no "
+                  "version specified.");
         return false;
     }
 
diff --git a/test/functional/wallet_multiwallet.py b/test/functional/wallet_multiwallet.py
--- a/test/functional/wallet_multiwallet.py
+++ b/test/functional/wallet_multiwallet.py
@@ -171,20 +171,6 @@
                 '-wallet=w2'],
             "Error: -salvagewallet is only allowed with a single wallet file")
 
-        self.log.info("Do not allow -upgradewallet with multiwallet")
-        self.nodes[0].assert_start_raises_init_error(
-            [
-                '-upgradewallet',
-                '-wallet=w1',
-                '-wallet=w2'],
-            "Error: -upgradewallet is only allowed with a single wallet file")
-        self.nodes[0].assert_start_raises_init_error(
-            [
-                '-upgradewallet=1',
-                '-wallet=w1',
-                '-wallet=w2'],
-            "Error: -upgradewallet is only allowed with a single wallet file")
-
         # if wallets/ doesn't exist, datadir should be the default wallet dir
         wallet_dir2 = data_dir('walletdir')
         os.rename(wallet_dir(), wallet_dir2)
@@ -426,25 +412,6 @@
         self.nodes[0].unloadwallet(wallet)
         self.nodes[1].loadwallet(wallet)
 
-        # Fail to load if wallet is downgraded
-        shutil.copytree(
-            os.path.join(
-                self.options.data_wallets_dir,
-                'high_minversion'),
-            wallet_dir('high_minversion'))
-        self.restart_node(
-            0, extra_args=[
-                '-upgradewallet={}'.format(FEATURE_LATEST)])
-        assert {'name': 'high_minversion'} in self.nodes[0].listwalletdir()[
-            'wallets']
-        self.log.info("Fail -upgradewallet that results in downgrade")
-        assert_raises_rpc_error(
-            -4,
-            'Wallet loading failed. Error loading {}: Wallet requires newer version of {}'.format(
-                wallet_dir('high_minversion', 'wallet.dat'), self.config['environment']['PACKAGE_NAME']),
-            lambda: self.nodes[0].loadwallet(filename='high_minversion'),
-        )
-
 
 if __name__ == '__main__':
     MultiWalletTest().main()