diff --git a/src/test/jtx/AMM.h b/src/test/jtx/AMM.h
index deadd80290..99131637bb 100644
--- a/src/test/jtx/AMM.h
+++ b/src/test/jtx/AMM.h
@@ -174,12 +174,22 @@ public:
     ammRpcInfo(
         std::optional<AccountID> const& account = std::nullopt,
         std::optional<std::string> const& ledgerIndex = std::nullopt,
-        std::optional<Asset> asset1 = std::nullopt,
-        std::optional<Asset> asset2 = std::nullopt,
+        std::optional<Asset> const& asset1 = std::nullopt,
+        std::optional<Asset> const& asset2 = std::nullopt,
         std::optional<AccountID> const& ammAccount = std::nullopt,
         bool ignoreParams = false,
         unsigned apiVersion = RPC::kApiInvalidVersion) const;
 
+    [[nodiscard]] json::Value
+    ammRpcInfo(
+        std::optional<json::Value> const& account,
+        std::optional<std::string> const& ledgerIndex,
+        std::optional<Asset> const& asset1,
+        std::optional<Asset> const& asset2,
+        std::optional<json::Value> const& ammAccount,
+        bool ignoreParams,
+        unsigned apiVersion) const;
+
     /** Verify the AMM balances.
      */
     [[nodiscard]] bool
diff --git a/src/test/jtx/impl/AMM.cpp b/src/test/jtx/impl/AMM.cpp
index c6dc14081a..2184f7e1b0 100644
--- a/src/test/jtx/impl/AMM.cpp
+++ b/src/test/jtx/impl/AMM.cpp
@@ -183,15 +183,37 @@ json::Value
 AMM::ammRpcInfo(
     std::optional<AccountID> const& account,
     std::optional<std::string> const& ledgerIndex,
-    std::optional<Asset> asset1,
-    std::optional<Asset> asset2,
+    std::optional<Asset> const& asset1,
+    std::optional<Asset> const& asset2,
     std::optional<AccountID> const& ammAccount,
     bool ignoreParams,
     unsigned apiVersion) const
+{
+    auto const toJson = [](AccountID const& a) { return json::Value{to_string(a)}; };
+
+    return ammRpcInfo(
+        account.transform(toJson),
+        ledgerIndex,
+        asset1,
+        asset2,
+        ammAccount.transform(toJson),
+        ignoreParams,
+        apiVersion);
+}
+
+json::Value
+AMM::ammRpcInfo(
+    std::optional<json::Value> const& account,
+    std::optional<std::string> const& ledgerIndex,
+    std::optional<Asset> const& asset1,
+    std::optional<Asset> const& asset2,
+    std::optional<json::Value> const& ammAccount,
+    bool ignoreParams,
+    unsigned apiVersion) const
 {
     json::Value jv;
     if (account)
-        jv[jss::account] = to_string(*account);
+        jv[jss::account] = *account;
     if (ledgerIndex)
         jv[jss::ledger_index] = *ledgerIndex;
     if (!ignoreParams)
@@ -209,7 +231,7 @@ AMM::ammRpcInfo(
             jv[jss::asset2] = STIssue(sfAsset2, asset2_.asset()).getJson(JsonOptions::Values::None);
         }
         if (ammAccount)
-            jv[jss::amm_account] = to_string(*ammAccount);
+            jv[jss::amm_account] = *ammAccount;
     }
     auto jr =
         (apiVersion == RPC::kApiInvalidVersion
diff --git a/src/test/rpc/AMMInfo_test.cpp b/src/test/rpc/AMMInfo_test.cpp
index 28c536aab9..987df6c724 100644
--- a/src/test/rpc/AMMInfo_test.cpp
+++ b/src/test/rpc/AMMInfo_test.cpp
@@ -65,6 +65,26 @@ public:
             BEAST_EXPECT(jv[jss::error_message] == "Account malformed.");
         });
 
+        // Account is not a string
+        testAMM([&](AMM& ammAlice, Env&) {
+            auto const jv =
+                ammAlice.ammRpcInfo(json::Value{42}, std::nullopt, XRP, USD, std::nullopt, true, 3);
+            BEAST_EXPECT(jv[jss::error_message] == "Account malformed.");
+        });
+
+        // AMM Account is not a string
+        testAMM([&](AMM& ammAlice, Env&) {
+            auto const jv = ammAlice.ammRpcInfo(
+                json::Value{to_string(ammAlice.ammAccount())},
+                std::nullopt,
+                XRP,
+                USD,
+                json::Value{42},
+                false,
+                3);
+            BEAST_EXPECT(jv[jss::error_message] == "Account malformed.");
+        });
+
         std::vector<std::tuple<std::optional<Issue>, std::optional<Issue>, TestAccount, bool>> const
             invalidParams = {
                 {xrpIssue(), std::nullopt, TestAccount::None, false},
diff --git a/src/xrpld/rpc/handlers/orderbook/AMMInfo.cpp b/src/xrpld/rpc/handlers/orderbook/AMMInfo.cpp
index 2c2f96b0e8..043fdd2d7b 100644
--- a/src/xrpld/rpc/handlers/orderbook/AMMInfo.cpp
+++ b/src/xrpld/rpc/handlers/orderbook/AMMInfo.cpp
@@ -120,7 +120,10 @@ doAMMInfo(RPC::JsonContext& context)
 
         if (params.isMember(jss::amm_account))
         {
-            auto const id = parseBase58<AccountID>((params[jss::amm_account].asString()));
+            auto const& ammAccount = params[jss::amm_account];
+            if (!ammAccount.isString())
+                return std::unexpected(RpcActMalformed);
+            auto const id = parseBase58<AccountID>(ammAccount.asString());
             if (!id)
                 return std::unexpected(RpcActMalformed);
             auto const sle = ledger->read(keylet::account(*id));
@@ -133,7 +136,10 @@ doAMMInfo(RPC::JsonContext& context)
 
         if (params.isMember(jss::account))
         {
-            accountID = parseBase58<AccountID>(params[jss::account].asString());
+            auto const& localAccount = params[jss::account];
+            if (!localAccount.isString())
+                return std::unexpected(RpcActMalformed);
+            accountID = parseBase58<AccountID>(localAccount.asString());
             if (!accountID || !ledger->read(keylet::account(*accountID)))
                 return std::unexpected(RpcActMalformed);
         }