diff --git a/mysql-test/main/func_json.result b/mysql-test/main/func_json.result
index 29f8c383abb..540c8244611 100644
--- a/mysql-test/main/func_json.result
+++ b/mysql-test/main/func_json.result
@@ -1646,5 +1646,16 @@ SELECT JSON_OBJECTAGG('\\', 1);
 JSON_OBJECTAGG('\\', 1)
 {"\\":1}
 #
+# MDEV-24784 JSON_ARRAYAGG charset issue
+#
+set names utf8;
+select json_arrayagg('ä'), json_objectagg(1, 'ä');
+json_arrayagg('ä')	json_objectagg(1, 'ä')
+["ä"]	{"1":"ä"}
+set names latin1;
+select json_arrayagg('ä'), json_objectagg(1, 'ä');
+json_arrayagg('ä')	json_objectagg(1, 'ä')
+["ä"]	{"1":"ä"}
+#
 # End of 10.5 tests
 #
diff --git a/mysql-test/main/func_json.test b/mysql-test/main/func_json.test
index c21fa8d05db..696ffa41a5a 100644
--- a/mysql-test/main/func_json.test
+++ b/mysql-test/main/func_json.test
@@ -1108,7 +1108,16 @@ SELECT JSON_OBJECTAGG('"', 1);
 SELECT JSON_OBJECTAGG('\"', 1);
 SELECT JSON_OBJECTAGG('\\', 1);
 
+--echo #
+--echo # MDEV-24784 JSON_ARRAYAGG charset issue
+--echo #
+--disable_service_connection
+set names utf8;
+select json_arrayagg('ä'), json_objectagg(1, 'ä');
+set names latin1;
+select json_arrayagg('ä'), json_objectagg(1, 'ä');
+--enable_service_connection
+
 --echo #
 --echo # End of 10.5 tests
 --echo #
-
diff --git a/sql/item_jsonfunc.cc b/sql/item_jsonfunc.cc
index b85adeff05d..1105406c658 100644
--- a/sql/item_jsonfunc.cc
+++ b/sql/item_jsonfunc.cc
@@ -3907,6 +3907,13 @@ int Arg_comparator::compare_e_json_str_basic(Item *j, Item *s)
   return MY_TEST(sortcmp(res1, res2, compare_collation()) == 0);
 }
 
+bool Item_func_json_arrayagg::fix_fields(THD *thd, Item **ref)
+{
+  bool res= Item_func_group_concat::fix_fields(thd, ref);
+  m_tmp_json.set_charset(collation.collation);
+  return res;
+}
+
 
 String *Item_func_json_arrayagg::get_str_from_item(Item *i, String *tmp)
 {
diff --git a/sql/item_jsonfunc.h b/sql/item_jsonfunc.h
index 4aaf66ec695..77936fcc4f4 100644
--- a/sql/item_jsonfunc.h
+++ b/sql/item_jsonfunc.h
@@ -570,6 +570,7 @@ public:
   }
 
   const char *func_name() const override { return "json_arrayagg("; }
+  bool fix_fields(THD *thd, Item **ref) override;
   enum Sumfunctype sum_func() const override { return JSON_ARRAYAGG_FUNC; }
 
   String* val_str(String *str) override;