diff --git a/packages/quicktype-core/src/language/CSharp/CSharpRenderer.ts b/packages/quicktype-core/src/language/CSharp/CSharpRenderer.ts
index 83a49e752..68b60b4ab 100644
--- a/packages/quicktype-core/src/language/CSharp/CSharpRenderer.ts
+++ b/packages/quicktype-core/src/language/CSharp/CSharpRenderer.ts
@@ -188,7 +188,7 @@ export class CSharpRenderer extends ConvenienceRenderer {
     ): Sourcelike {
         t = followTargetType(t);
         const csType = this.csType(t, follow, withIssues);
-        if (isValueType(t)) {
+        if (isValueType(t) || this._csOptions.version >= 8) {
             return [csType, "?"];
         } else {
             return csType;
diff --git a/packages/quicktype-core/src/language/CSharp/SystemTextJsonCSharpRenderer.ts b/packages/quicktype-core/src/language/CSharp/SystemTextJsonCSharpRenderer.ts
index d61a74ecc..08a4de9e8 100644
--- a/packages/quicktype-core/src/language/CSharp/SystemTextJsonCSharpRenderer.ts
+++ b/packages/quicktype-core/src/language/CSharp/SystemTextJsonCSharpRenderer.ts
@@ -273,7 +273,9 @@ export class SystemTextJsonCSharpRenderer extends CSharpRenderer {
         const isNullable = followTargetType(property.type).isNullable;
         const isOptional = property.isOptional;
 
-        if (isOptional && !isNullable) {
+        if (!isOptional) {
+            attributes.push(["[", "JsonRequired", "]"]);
+        } else if (isOptional && !isNullable) {
             attributes.push([
                 "[",
                 "JsonIgnore",
diff --git a/packages/quicktype-core/src/language/CSharp/language.ts b/packages/quicktype-core/src/language/CSharp/language.ts
index 79562aa27..3bc196fed 100644
--- a/packages/quicktype-core/src/language/CSharp/language.ts
+++ b/packages/quicktype-core/src/language/CSharp/language.ts
@@ -69,6 +69,7 @@ export const cSharpOptions = {
         {
             "5": 5,
             "6": 6,
+            "8": 8,
         } as const,
         "6",
         "secondary",