diff --git a/common/generate_packets.py b/common/generate_packets.py
index df033fcd4e..e3bf3be10d 100755
--- a/common/generate_packets.py
+++ b/common/generate_packets.py
@@ -1476,11 +1476,11 @@ def _get_code_put_diff(self, location: Location) -> str:
       {location.json_subloc}->number = -1;
 
       /* Create the diff array element. */
-      e |= DIO_PUT(farray, &dout, &field_addr, 2);
+      e |= DIO_PUT(object, &dout, &field_addr);
 
       /* Enter diff array element (start at the index address). */
       {location.json_subloc}->number = count_{location.index}++;
-      {location.json_subloc}->sub_location = plocation_elem_new(0);
+      {location.json_subloc}->sub_location = plocation_field_new("index");
 #endif /* FREECIV_JSON_CONNECTION */
 
       /* Write the index */
@@ -1488,7 +1488,7 @@ def _get_code_put_diff(self, location: Location) -> str:
 
 #ifdef FREECIV_JSON_CONNECTION
       /* Content address. */
-      {location.json_subloc}->sub_location->number = 1;
+      {location.json_subloc}->sub_location->name = "data";
 #endif /* FREECIV_JSON_CONNECTION */
 
 {inner_put}\
@@ -1505,11 +1505,11 @@ def _get_code_put_diff(self, location: Location) -> str:
   {location.json_subloc}->number = -1;
 
   /* Create the terminating diff array element. */
-  e |= DIO_PUT(farray, &dout, &field_addr, 1);
+  e |= DIO_PUT(object, &dout, &field_addr);
 
   /* Enter diff array element (start at the index address). */
   {location.json_subloc}->number = count_{location.index};
-  {location.json_subloc}->sub_location = plocation_elem_new(0);
+  {location.json_subloc}->sub_location = plocation_field_new("index");
 #endif /* FREECIV_JSON_CONNECTION */
 
   /* Write the sentinel value */
@@ -1571,7 +1571,7 @@ def _get_code_get_diff(self, location: Location) -> str:
 /* Enter array (start at initial element). */
 {location.json_subloc} = plocation_elem_new(0);
 /* Enter diff array element (start at the index address). */
-{location.json_subloc}->sub_location = plocation_elem_new(0);
+{location.json_subloc}->sub_location = plocation_field_new("index");
 #endif /* FREECIV_JSON_CONNECTION */
 
 while (TRUE) {{
@@ -1592,7 +1592,7 @@ def _get_code_get_diff(self, location: Location) -> str:
 
 #ifdef FREECIV_JSON_CONNECTION
   /* Content address. */
-  {location.json_subloc}->sub_location->number = 1;
+  {location.json_subloc}->sub_location->name = "data";
 #endif /* FREECIV_JSON_CONNECTION */
 
 {inner_get}\
@@ -1601,7 +1601,7 @@ def _get_code_get_diff(self, location: Location) -> str:
   /* Move to the next diff array element. */
   {location.json_subloc}->number++;
   /* Back to the index address. */
-  {location.json_subloc}->sub_location->number = 0;
+  {location.json_subloc}->sub_location->name = "index";
 #endif /* FREECIV_JSON_CONNECTION */
 }}
 
diff --git a/common/networking/dataio_json.c b/common/networking/dataio_json.c
index 9b5fa69ef1..59ba289560 100644
--- a/common/networking/dataio_json.c
+++ b/common/networking/dataio_json.c
@@ -120,22 +120,12 @@ static int plocation_write_elem(json_t *item,
       e = json_array_set_new(item, location->number, data);
     }
   } else {
-    // PTZ200718 handles last element get case...
-    // better here than all around put_array-diff algo ?
     size_t n = (location->number == -1)
       ? (json_array_size(item) - 1)
       : location->number;
 
-    json_t *sub_item = json_array_get(item, n);
-
-    if (json_is_array(sub_item)) {
-      e = plocation_write_data(sub_item,
-                               location->sub_location, data);
-    } else {
-      log_error("ERROR:plocation_write_elem:array not found for sub location:"
-                "%s @[" SIZE_T_PRINTF "]",
-                json_dumps(item, JSON_DECODE_ANY), location->number);
-    }
+    e = plocation_write_data(json_array_get(item, n),
+                             location->sub_location, data);
   }
 
   return e;
@@ -921,6 +911,23 @@ int dio_put_farray_json(struct json_data_out *dout,
   return e;
 }
 
+/**********************************************************************//**
+  Create an empty JSON object.
+**************************************************************************/
+int dio_put_object_json(struct json_data_out *dout,
+                        const struct plocation *location)
+{
+  int e = 0;
+
+  if (dout->json) {
+    e |= plocation_write_data(dout->json, location, json_object());
+  } else {
+    /* No caller needs this */
+  }
+
+  return e;
+}
+
 /**********************************************************************//**
   Insert uint32 value.
 **************************************************************************/
diff --git a/common/networking/dataio_json.h b/common/networking/dataio_json.h
index 06b242600b..2739a83e60 100644
--- a/common/networking/dataio_json.h
+++ b/common/networking/dataio_json.h
@@ -130,6 +130,8 @@ bool dio_get_uint16_vec8_json(struct connection *pc, struct data_in *din,
 /* puts */
 int dio_put_farray_json(struct json_data_out *dout,
                         const struct plocation *location, int size);
+int dio_put_object_json(struct json_data_out *dout,
+                        const struct plocation *location);
 
 int dio_put_type_json(struct json_data_out *dout, enum data_type type,
                       const struct plocation *location,