diff --git a/src/test/rpc/RPCCall_test.cpp b/src/test/rpc/RPCCall_test.cpp
index c9c1ad548a..45914efd2d 100644
--- a/src/test/rpc/RPCCall_test.cpp
+++ b/src/test/rpc/RPCCall_test.cpp
@@ -2413,8 +2413,16 @@ static RPCCallTestData const rpcCallTestArray[] = {
          "ThereIsNoCheckingOnTheIPFormat",
          "-1",
      },
-     RPCCallTestData::bad_cast,
-     R"()"},
+     RPCCallTestData::no_exception,
+     R"({
+   "method" : "connect",
+   "params" : [
+      {
+         "error" : "invalidParams",
+         "error_message" : "Invalid field 'port'."
+      }
+   ]
+})"},
     {// Note: this should return an error but not throw.
      "connect: port too large.",
      __LINE__,
@@ -2423,8 +2431,16 @@ static RPCCallTestData const rpcCallTestArray[] = {
          "ThereIsNoCheckingOnTheIPFormat",
          "4294967296",
      },
-     RPCCallTestData::bad_cast,
-     R"()"},
+     RPCCallTestData::no_exception,
+     R"({
+   "method" : "connect",
+   "params" : [
+      {
+         "error" : "invalidParams",
+         "error_message" : "Invalid field 'port'."
+      }
+   ]
+})"},
 
     // consensus_info
     // --------------------------------------------------------------
diff --git a/src/xrpld/rpc/detail/RPCCall.cpp b/src/xrpld/rpc/detail/RPCCall.cpp
index ca8af78950..09af2b9db1 100644
--- a/src/xrpld/rpc/detail/RPCCall.cpp
+++ b/src/xrpld/rpc/detail/RPCCall.cpp
@@ -455,7 +455,10 @@ private:
         if (jvParams.size() == 2)
         {
             jvRequest[jss::ip] = ip;
-            jvRequest[jss::port] = jvParams[1u].asUInt();
+            if (auto port = jvParseUInt(jvParams[1u]))
+                jvRequest[jss::port] = *port;
+            else
+                return RPC::invalid_field_error(jss::port);
             return jvRequest;
         }
 
@@ -464,8 +467,13 @@ private:
         {
             std::size_t colon = ip.find_last_of(":");
             jvRequest[jss::ip] = std::string{ip, 0, colon};
-            jvRequest[jss::port] =
-                Json::Value{std::string{ip, colon + 1}}.asUInt();
+
+            std::uint32_t port;
+            if (beast::lexicalCastChecked(port, std::string{ip, colon + 1}))
+                jvRequest[jss::port] = port;
+            else
+                return RPC::invalid_field_error(jss::port);
+
             return jvRequest;
         }