diff --git a/src/test/rpc/RPCCall_test.cpp b/src/test/rpc/RPCCall_test.cpp
index 7647dc5f65..f17d87884a 100644
--- a/src/test/rpc/RPCCall_test.cpp
+++ b/src/test/rpc/RPCCall_test.cpp
@@ -1381,16 +1381,32 @@ static RPCCallTestData const rpcCallTestArray[] = {
         "account_tx: non-integer min.",
         __LINE__,
         {"account_tx", "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh", "Binary", "-1"},
-        RPCCallTestData::bad_cast,
-        R"()",
+        RPCCallTestData::no_exception,
+        R"({
+   "method" : "account_tx",
+   "params" : [
+      {
+         "error" : "invalidLgrRange",
+         "error_message" : "Ledger range is invalid."
+      }
+   ]
+})",
     },
     {
         // Note: this really shouldn't throw, but does at the moment.
         "account_tx: non-integer max.",
         __LINE__,
         {"account_tx", "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh", "-1", "counts"},
-        RPCCallTestData::bad_cast,
-        R"()",
+        RPCCallTestData::no_exception,
+        R"({
+   "method" : "account_tx",
+   "params" : [
+      {
+         "error" : "invalidLgrRange",
+         "error_message" : "Ledger range is invalid."
+      }
+   ]
+})",
     },
     {
         // Note: this really shouldn't throw, but does at the moment.
@@ -1400,25 +1416,39 @@ static RPCCallTestData const rpcCallTestArray[] = {
          "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh",
          "-1",
          "-1",
-         "decending"},
-        RPCCallTestData::bad_cast,
-        R"()",
+         "200",
+         "bad_offset"},
+        RPCCallTestData::no_exception,
+        R"({
+   "method" : "account_tx",
+   "params" : [
+      {
+         "error" : "invalidParams",
+         "error_message" : "Invalid field 'offset'."
+      }
+   ]
+})",
     },
     {
-        // Note: this really shouldn't throw, but does at the moment.
         "account_tx: non-integer limit.",
         __LINE__,
         {"account_tx",
          "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh",
          "-1",
          "-1",
-         "300",
-         "false"},
-        RPCCallTestData::bad_cast,
-        R"()",
+         "bad_limit"},
+        RPCCallTestData::no_exception,
+        R"({
+   "method" : "account_tx",
+   "params" : [
+      {
+         "error" : "invalidParams",
+         "error_message" : "Invalid field 'limit'."
+      }
+   ]
+})",
     },
-    {// Note: this really shouldn't throw, but does at the moment.
-     "account_tx: RIPD-1570.",
+    {"account_tx: RIPD-1570.",
      __LINE__,
      {"account_tx",
       "rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh",
@@ -1428,8 +1458,16 @@ static RPCCallTestData const rpcCallTestArray[] = {
       "false",
       "false",
       "false"},
-     RPCCallTestData::bad_cast,
-     R"()"},
+     RPCCallTestData::no_exception,
+     R"({
+   "method" : "account_tx",
+   "params" : [
+      {
+         "error" : "invalidParams",
+         "error_message" : "Invalid field 'offset'."
+      }
+   ]
+})"},
 
     // book_offers
     // -----------------------------------------------------------------
@@ -5978,6 +6016,10 @@ public:
             }
             else
             {
+                std::cout << "no match: " << rpcCallTest.description
+                          << std::endl;
+                std::cout << "  got: " << got.toStyledString() << std::endl;
+                std::cout << "  exp: " << exp.toStyledString() << std::endl;
                 fail(rpcCallTest.description, __FILE__, rpcCallTest.line);
             }
         }
diff --git a/src/xrpld/rpc/detail/RPCCall.cpp b/src/xrpld/rpc/detail/RPCCall.cpp
index 185043302a..8ca2548aea 100644
--- a/src/xrpld/rpc/detail/RPCCall.cpp
+++ b/src/xrpld/rpc/detail/RPCCall.cpp
@@ -135,6 +135,22 @@ private:
         }
     }
 
+    static std::optional<std::uint32_t>
+    jvParseInt(Json::Value const& param)
+    {
+        if (param.isUInt() || param.isInt())
+            return param.asInt();
+
+        if (param.isString())
+        {
+            std::int32_t v;
+            if (beast::lexicalCastChecked(v, param.asString()))
+                return v;
+        }
+
+        return std::nullopt;
+    }
+
     static bool
     validPublicKey(
         std::string const& strPk,
@@ -266,24 +282,50 @@ private:
         }
         else
         {
-            std::int64_t uLedgerMin = jvParams[1u].asInt();
-            std::int64_t uLedgerMax = jvParams[2u].asInt();
+            std::int32_t ledgerMin, ledgerMax;
+            if (auto ledgerMinOpt = jvParseInt(jvParams[1u]))
+            {
+                ledgerMin = *ledgerMinOpt;
+            }
+            else
+            {
+                return rpcError(rpcINVALID_LGR_RANGE);
+            }
 
-            if (uLedgerMax != -1 && uLedgerMax < uLedgerMin)
+            if (auto ledgerMaxOpt = jvParseInt(jvParams[2u]))
+            {
+                ledgerMax = *ledgerMaxOpt;
+            }
+            else
+            {
+                return rpcError(rpcINVALID_LGR_RANGE);
+            }
+
+            if (ledgerMax != -1 && ledgerMax < ledgerMin)
             {
                 if (apiVersion_ == 1)
                     return rpcError(rpcLGR_IDXS_INVALID);
                 return rpcError(rpcNOT_SYNCED);
             }
 
-            jvRequest[jss::ledger_index_min] = jvParams[1u].asInt();
-            jvRequest[jss::ledger_index_max] = jvParams[2u].asInt();
+            jvRequest[jss::ledger_index_min] = ledgerMin;
+            jvRequest[jss::ledger_index_max] = ledgerMax;
 
             if (iParams >= 4)
-                jvRequest[jss::limit] = jvParams[3u].asInt();
+            {
+                if (auto limit = jvParseInt(jvParams[3u]))
+                    jvRequest[jss::limit] = *limit;
+                else
+                    return RPC::invalid_field_error(jss::limit);
+            }
 
             if (iParams >= 5)
-                jvRequest[jss::offset] = jvParams[4u].asInt();
+            {
+                if (auto offset = jvParseInt(jvParams[4u]))
+                    jvRequest[jss::offset] = *offset;
+                else
+                    return RPC::invalid_field_error(jss::offset);
+            }
         }
 
         return jvRequest;