diff --git a/compiler/src/model/build-model.ts b/compiler/src/model/build-model.ts
index 7c87f19fd0..c3e196ffa7 100644
--- a/compiler/src/model/build-model.ts
+++ b/compiler/src/model/build-model.ts
@@ -285,6 +285,10 @@ function compileClassOrInterfaceDeclaration (declaration: ClassDeclaration | Int
       // validate body
       // the body can either be a value (eg Array<string> or an object with properties)
       if (bodyValue != null) {
+        // Propagate required body value nature based on TS question token being present.
+        // Overrides the value set by spec files.
+        mapping.requestBodyRequired = !(bodyMember as PropertySignature).hasQuestionToken()
+
         if (bodyValue.kind === 'instance_of' && bodyValue.type.name === 'Void') {
           assert(bodyMember as Node, false, 'There is no need to use Void in requets definitions, just remove the body declaration.')
         } else {
@@ -299,6 +303,7 @@ function compileClassOrInterfaceDeclaration (declaration: ClassDeclaration | Int
             !type.path.map(p => p.codegenName ?? p.name).concat(type.query.map(p => p.codegenName ?? p.name)).includes(tags.codegen_name),
             `The codegen_name '${tags.codegen_name}' already exists as a property in the path or query.`
           )
+
           type.body = {
             kind: 'value',
             value: bodyValue,
diff --git a/compiler/src/steps/validate-rest-spec.ts b/compiler/src/steps/validate-rest-spec.ts
index ba811c6cba..35f9fdf8e4 100644
--- a/compiler/src/steps/validate-rest-spec.ts
+++ b/compiler/src/steps/validate-rest-spec.ts
@@ -122,6 +122,10 @@ export default async function validateRestSpec (model: model.Model, jsonSpec: Ma
       if (requestProperties.body === Body.noBody && spec.body != null && spec.body.required === true) {
         errors.addEndpointError(endpoint.name, 'request', `${endpoint.request.name}: should have a body definition`)
       }
+
+      if (spec.body != null && spec.body.required === true && spec.body.required !== endpoint.requestBodyRequired) {
+        errors.addEndpointError(endpoint.name, 'request', ': should not be an optional body definition')
+      }
     }
   }