diff --git a/Zabbix/Entities/Item.cs b/Zabbix/Entities/Item.cs
index 6015da1..03af6c2 100644
--- a/Zabbix/Entities/Item.cs
+++ b/Zabbix/Entities/Item.cs
@@ -39,7 +39,7 @@ public class Item : BaseEntity
 
     [JsonProperty("valuemapid")] public string? Valuemapid { get; set; }
 
-    [JsonProperty("params")] public string? Params { get; set; }
+    [JsonProperty("params")] public Dictionary<string, string>? Params { get; set; }
 
     [JsonProperty("ipmi_sensor")] public string? IpmiSensor { get; set; }
 
@@ -71,7 +71,7 @@ public class Item : BaseEntity
 
     [JsonProperty("url")] public string? Url { get; set; }
 
-    [JsonProperty("query_fields")] public object? QueryFields { get; set; } //TODO: map this to something else
+    [JsonProperty("query_fields")] public List<object>? QueryFields { get; set; } 
 
     [JsonProperty("posts")] public string? Posts { get; set; }
 
@@ -83,7 +83,7 @@ public class Item : BaseEntity
 
     [JsonProperty("http_proxy")] public string? HttpProxy { get; set; }
 
-    [JsonProperty("headers")] public HttpField? Headers { get; set; } //TODO make this something thats not object, bug: doesnt work with list of httpfields, above and below are two more with same problem
+    [JsonProperty("headers")] public Dictionary<string, string>? Headers { get; set; } 
 
     [JsonProperty("retrieve_mode")] public int? RetrieveMode { get; set; }
 
@@ -109,7 +109,8 @@ public class Item : BaseEntity
 
     [JsonProperty("error")] public string? Error { get; set; }
 
-    [JsonProperty("parameters")] public object? Parameters { get; set; }
+    [JsonProperty("parameters")] public List<object>? Parameters { get; set; }
+
 
     [JsonProperty("lastclock")] public string? Lastclock { get; set; }
 
@@ -167,7 +168,7 @@ public class ItemPreprocessing
 
     [JsonProperty("type")] public int? Type { get; set; }
 
-    [JsonProperty("params")] public string? Params { get; set; }
+    [JsonProperty("params")] public Dictionary<string, string>? Params { get; set; }
 
     [JsonProperty("error_handler")] public int? ErrorHandler { get; set; }
 
@@ -177,7 +178,7 @@ public class ItemPreprocessing
 
     #region Constructors
 
-    public ItemPreprocessing(int type, string @params, int errorHandler, string errorHandlerParams)
+    public ItemPreprocessing(int type, Dictionary<string, string> @params, int errorHandler, string errorHandlerParams)
     {
         Type = type;
         Params = @params;
diff --git a/Zabbix/Entities/ItemPrototype.cs b/Zabbix/Entities/ItemPrototype.cs
index 52c0619..dcb560b 100644
--- a/Zabbix/Entities/ItemPrototype.cs
+++ b/Zabbix/Entities/ItemPrototype.cs
@@ -49,7 +49,7 @@ public class ItemPrototype : BaseEntity
         public int? FollowRedirects { get; set; }
 
         [JsonProperty("headers")]
-        public HttpField? Headers { get; set; }
+        public Dictionary<string, string>? Headers { get; set; }
 
         [JsonProperty("history")]
         public string? History { get; set; }
@@ -73,7 +73,7 @@ public class ItemPrototype : BaseEntity
         public int? OutputFormat { get; set; }
 
         [JsonProperty("params")]
-        public string? Params { get; set; }
+        public Dictionary<string, string>? Params { get; set; }
 
         [JsonProperty("parameters")]
         public IList<object>? Parameters { get; set; }
@@ -218,7 +218,7 @@ public class ItemPrototypePreprocessing
         public int? Type { get; set; }
 
         [JsonProperty("params")]
-        public string? Params { get; set; }
+        public Dictionary<string, string>? Params { get; set; }
 
         [JsonProperty("error_handler")]
         public int? ErrorHandler { get; set; }
@@ -230,7 +230,7 @@ public class ItemPrototypePreprocessing
 
         #region Constructors
 
-        public ItemPrototypePreprocessing(int type, string @params, int errorHandler, string errorHandlerParams)
+        public ItemPrototypePreprocessing(int type, Dictionary<string, string> @params, int errorHandler, string errorHandlerParams)
         {
             Type = type;
             Params = @params;
diff --git a/Zabbix/Entities/LLDRule.cs b/Zabbix/Entities/LLDRule.cs
index b95526a..3d76b98 100644
--- a/Zabbix/Entities/LLDRule.cs
+++ b/Zabbix/Entities/LLDRule.cs
@@ -65,7 +65,7 @@ public class LldRule : BaseEntity
         public int? OutputFormat { get; set; }
 
         [JsonProperty("params")]
-        public string? Params { get; set; }
+        public Dictionary<string, string>? Params { get; set; }
 
         [JsonProperty("password")]
         public string? Password { get; set; }
@@ -135,7 +135,7 @@ public class LldRule : BaseEntity
         #region Components
 
         [JsonProperty("headers")]
-        public object? Headers { get; set; }
+        public Dictionary<string, string>? Headers { get; set; }
 
         [JsonProperty("parameters")]
         public IList<object>? Parameters { get; set; }
@@ -272,7 +272,7 @@ public class LLdRulePreprocessing
         public int? Type { get; set; }
 
         [JsonProperty("params")]
-        public string? Params { get; set; }
+        public Dictionary<string, string>? Params { get; set; }
 
         [JsonProperty("error_handler")]
         public int? ErrorHandler { get; set; }
@@ -284,7 +284,7 @@ public class LLdRulePreprocessing
 
         #region Constructors
 
-        public LLdRulePreprocessing(int type, string @params, int errorHandler, string errorHandlerParams)
+        public LLdRulePreprocessing(int type, Dictionary<string, string> @params, int errorHandler, string errorHandlerParams)
         {
             Type = type;
             Params = @params;
diff --git a/Zabbix/Zabbix.csproj b/Zabbix/Zabbix.csproj
index 05f725e..467d30c 100644
--- a/Zabbix/Zabbix.csproj
+++ b/Zabbix/Zabbix.csproj
@@ -8,7 +8,7 @@
     <Title>Zabbix 6.0 API Library</Title>
     <Authors>Stefan Hasler</Authors>
     <Company />
-	  <Version>1.2.3</Version>
+	  <Version>1.2.4</Version>
     <PackageId>$(AssemblyName).Api.NET</PackageId>
     <Product />
     <Description>Library to communicate with the 6.0 Zabbix Api</Description>