diff --git a/src/NSwag.CodeGeneration.CSharp/Models/CSharpOperationModel.cs b/src/NSwag.CodeGeneration.CSharp/Models/CSharpOperationModel.cs
index 0c11abc0b..6127c0ebc 100644
--- a/src/NSwag.CodeGeneration.CSharp/Models/CSharpOperationModel.cs
+++ b/src/NSwag.CodeGeneration.CSharp/Models/CSharpOperationModel.cs
@@ -113,7 +113,9 @@ public string MethodAccessModifier
         /// <summary>
         /// The default value of the result type, i.e. default(T) or default(T)! depending on whether NRT are enabled.
         /// </summary>
-        public string UnwrappedResultDefaultValue => $"default({UnwrappedResultType}){((_settings as CSharpClientGeneratorSettings)?.CSharpGeneratorSettings.GenerateNullableReferenceTypes == true ? "!" : "")}";
+        public string UnwrappedResultDefaultValue => HasResult 
+            ? $"default({UnwrappedResultType}){((_settings as CSharpClientGeneratorSettings)?.CSharpGeneratorSettings.GenerateNullableReferenceTypes == true ? "!" : "")}"
+            : null;
 
         /// <summary>Gets or sets the synchronous type of the result.</summary>
         public string SyncResultType
diff --git a/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.ProcessResponse.liquid b/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.ProcessResponse.liquid
index 9201c5893..bc037fc58 100644
--- a/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.ProcessResponse.liquid
+++ b/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.ProcessResponse.liquid
@@ -57,7 +57,7 @@ throw new {{ ExceptionClass }}<{{ response.Type }}>("{{ response.ExceptionDescri
 {%         if operation.WrapResponse -%}
 return new {{ ResponseClass }}<{{ operation.UnwrappedResultType }}>(status_, headers_, {{ operation.UnwrappedResultDefaultValue }});
 {%         else -%}
-return {{ operation.UnwrappedResultDefaultValue }};
+{%             if operation.HasResult %}return {{ operation.UnwrappedResultDefaultValue }};{% else %}return;{% endif %}
 {%         endif -%}
 {%     else -%}
 {%         if operation.WrapResponse -%}
diff --git a/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.liquid b/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.liquid
index 584842c89..0d9cf0661 100644
--- a/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.liquid
+++ b/src/NSwag.CodeGeneration.CSharp/Templates/Client.Class.liquid
@@ -407,7 +407,7 @@
 {%             if operation.WrapResponse and operation.UnwrappedResultType != "FileResponse" %}
                     return new {{ ResponseClass }}<{{ operation.UnwrappedResultType }}>(status_, headers_, {{ operation.UnwrappedResultDefaultValue }});
 {%             else -%}
-                    return {{ operation.UnwrappedResultDefaultValue }};
+                    {% if operation.HasResult %}return {{ operation.UnwrappedResultDefaultValue }};{% else %}return;{% endif %}
 {%             endif -%}
 {%         elsif operation.WrapResponse -%}
                     return new {{ ResponseClass }}(status_, headers_);
@@ -425,7 +425,7 @@
 {%                 if operation.WrapResponse and operation.UnwrappedResultType != "FileResponse" %}
                         return new {{ ResponseClass }}<{{ operation.UnwrappedResultType }}>(status_, headers_, {{ operation.UnwrappedResultDefaultValue }});
 {%                 else -%}
-                        return {{ operation.UnwrappedResultDefaultValue }};
+                        {% if operation.HasResult %}return {{ operation.UnwrappedResultDefaultValue }};{% else %}return;{% endif %}
 {%                 endif -%}
 {%             elsif operation.WrapResponse -%}
                         return new {{ ResponseClass }}(status_, headers_);