diff --git a/doc/release-notes.md b/doc/release-notes.md
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -4,3 +4,9 @@
 
 This release includes the following features and fixes:
  -
+
+Low-level RPC changes
+----------------------
+ - `-usehd` was removed in version 0.16. From that version onwards, all new
+ wallets created are hierarchical deterministic wallets. Version 0.18 makes
+ specifying `-usehd` invalid config.
diff --git a/src/init.cpp b/src/init.cpp
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -348,7 +348,7 @@
     std::vector<std::string> hidden_args = {
         "-rpcssl", "-benchmark", "-h", "-help", "-socks", "-tor", "-debugnet",
         "-whitelistalwaysrelay", "-blockminsize", "-dbcrashratio",
-        "-forcecompactdb", "-usehd", "-parkdeepreorg", "-automaticunparking",
+        "-forcecompactdb", "-parkdeepreorg", "-automaticunparking",
         "-replayprotectionactivationtime", "-enableminerfund",
         // GUI args. These will be overwritten by SetupUIArgs for the GUI
         "-allowselfsignedrootcertificates", "-choosedatadir", "-lang=<lang>",
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -4523,12 +4523,6 @@
     if (fFirstRun) {
         // Ensure this wallet.dat can only be opened by clients supporting
         // HD with chain split and expects no default key.
-        if (!gArgs.GetBoolArg("-usehd", true)) {
-            InitError(strprintf(_("Error creating %s: You can't create non-HD "
-                                  "wallets with this version."),
-                                walletFile));
-            return nullptr;
-        }
         walletInstance->SetMinVersion(FEATURE_LATEST);
 
         if ((wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
@@ -4567,22 +4561,6 @@
                                     "{%s} with disabled private keys"),
                                   walletFile));
         }
-    } else if (gArgs.IsArgSet("-usehd")) {
-        bool useHD = gArgs.GetBoolArg("-usehd", true);
-        if (walletInstance->IsHDEnabled() && !useHD) {
-            InitError(
-                strprintf(_("Error loading %s: You can't disable HD on an "
-                            "already existing HD wallet"),
-                          walletFile));
-            return nullptr;
-        }
-
-        if (!walletInstance->IsHDEnabled() && useHD) {
-            InitError(strprintf(_("Error loading %s: You can't enable HD on an "
-                                  "already existing non-HD wallet"),
-                                walletFile));
-            return nullptr;
-        }
     }
 
     if (gArgs.IsArgSet("-mintxfee")) {
diff --git a/test/functional/wallet_hd.py b/test/functional/wallet_hd.py
--- a/test/functional/wallet_hd.py
+++ b/test/functional/wallet_hd.py
@@ -25,13 +25,6 @@
         self.skip_if_no_wallet()
 
     def run_test(self):
-        # Make sure can't switch off usehd after wallet creation
-        self.stop_node(1)
-        self.nodes[1].assert_start_raises_init_error(
-            ['-usehd=0'], "Error: Error loading : You can't disable HD on an already existing HD wallet")
-        self.start_node(1)
-        connect_nodes_bi(self.nodes[0], self.nodes[1])
-
         # Make sure we use hd, keep masterkeyid
         masterkeyid = self.nodes[1].getwalletinfo()['hdseedid']
         assert_equal(masterkeyid, self.nodes[1].getwalletinfo()[
diff --git a/test/lint/check-doc.py b/test/lint/check-doc.py
--- a/test/lint/check-doc.py
+++ b/test/lint/check-doc.py
@@ -45,7 +45,6 @@
                                        '-rpcssl',
                                        '-socks',
                                        '-tor',
-                                       '-usehd',
                                        '-whitelistalwaysrelay'])