diff --git a/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.QueryParameter.liquid b/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.QueryParameter.liquid
index 3a6ea85864..e9984f17e1 100644
--- a/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.QueryParameter.liquid
+++ b/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.QueryParameter.liquid
@@ -39,6 +39,7 @@ if ({{parameter.Name}}.{{property.Name}} != null)
 {% elsif parameter.HasAdditionalProperties == false -%}
 urlBuilder_.Append(System.Uri.EscapeDataString("{{ parameter.Name }}")).Append('=').Append(System.Uri.EscapeDataString({% if parameter.IsNullable and parameter.IsRequired %}{{ parameter.VariableName }} != null ? {% endif %}ConvertToString({{ parameter.VariableName }}, System.Globalization.CultureInfo.InvariantCulture){% if parameter.IsNullable and parameter.IsRequired %} : "{{ QueryNullValue }}"{% endif %})).Append('&');
 {% endif -%}
-{% if parameter.HasAdditionalProperties -%}
+{% if parameter.HasAdditionalProperties and parameter.IsDeepObject == false -%}
 foreach (var item_ in {{parameter.Name}}.AdditionalProperties) { urlBuilder_.Append(System.Uri.EscapeDataString(item_.Key)).Append('=').Append(System.Uri.EscapeDataString(ConvertToString(item_.Value, System.Globalization.CultureInfo.InvariantCulture))).Append('&'); }
+{% elsif parameter.HasAdditionalProperties and parameter.IsDeepObject -%}foreach (var item_ in {{parameter.Name}}.AdditionalProperties) { urlBuilder_.Append(System.Uri.EscapeDataString("{{parameter.Name}}[{{item_.Key}}]")).Append('=').Append(System.Uri.EscapeDataString(ConvertToString(item_.Value, System.Globalization.CultureInfo.InvariantCulture))).Append('&'); }
 {% endif -%}