diff --git a/src/wallet/init.cpp b/src/wallet/init.cpp
--- a/src/wallet/init.cpp
+++ b/src/wallet/init.cpp
@@ -174,23 +174,23 @@
         }
     }
 
-    int zapwallettxes = gArgs.GetArg("-zapwallettxes", 0);
+    bool zapwallettxes = gArgs.GetBoolArg("-zapwallettxes", false);
     // -zapwallettxes implies dropping the mempool on startup
-    if (zapwallettxes != 0 && gArgs.SoftSetBoolArg("-persistmempool", false)) {
-        LogPrintf("%s: parameter interaction: -zapwallettxes=%s -> setting "
-                  "-persistmempool=0\n",
-                  __func__, zapwallettxes);
+    if (zapwallettxes && gArgs.SoftSetBoolArg("-persistmempool", false)) {
+        LogPrintf("%s: parameter interaction: -zapwallettxes enabled -> "
+                  "setting -persistmempool=0\n",
+                  __func__);
     }
 
     // -zapwallettxes implies a rescan
-    if (zapwallettxes != 0) {
+    if (zapwallettxes) {
         if (is_multiwallet) {
             return InitError(
                 strprintf("%s is only allowed with a single wallet file",
                           "-zapwallettxes"));
         }
         if (gArgs.SoftSetBoolArg("-rescan", true)) {
-            LogPrintf("%s: parameter interaction: -zapwallettxes=<mode> -> "
+            LogPrintf("%s: parameter interaction: -zapwallettxes enabled -> "
                       "setting -rescan=1\n",
                       __func__);
         }
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
@@ -114,6 +114,54 @@
         self.nodes[0].assert_start_raises_init_error(
             ['-walletdir=' + not_a_dir], 'Error: Specified -walletdir "' + not_a_dir + '" is not a directory')
 
+        self.log.info("Do not allow -zapwallettxes with multiwallet")
+        self.nodes[0].assert_start_raises_init_error(
+            [
+                '-zapwallettxes',
+                '-wallet=w1',
+                '-wallet=w2'],
+            "Error: -zapwallettxes is only allowed with a single wallet file")
+        self.nodes[0].assert_start_raises_init_error(
+            [
+                '-zapwallettxes=1',
+                '-wallet=w1',
+                '-wallet=w2'],
+            "Error: -zapwallettxes is only allowed with a single wallet file")
+        self.nodes[0].assert_start_raises_init_error(
+            [
+                '-zapwallettxes=2',
+                '-wallet=w1',
+                '-wallet=w2'],
+            "Error: -zapwallettxes is only allowed with a single wallet file")
+
+        self.log.info("Do not allow -salvagewallet with multiwallet")
+        self.nodes[0].assert_start_raises_init_error(
+            [
+                '-salvagewallet',
+                '-wallet=w1',
+                '-wallet=w2'],
+            "Error: -salvagewallet is only allowed with a single wallet file")
+        self.nodes[0].assert_start_raises_init_error(
+            [
+                '-salvagewallet=1',
+                '-wallet=w1',
+                '-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)