diff --git a/generated/src/aws-cpp-sdk-s3-crt/source/S3CrtClient.cpp b/generated/src/aws-cpp-sdk-s3-crt/source/S3CrtClient.cpp
index efefb5b03f1..9c628d70ea3 100644
--- a/generated/src/aws-cpp-sdk-s3-crt/source/S3CrtClient.cpp
+++ b/generated/src/aws-cpp-sdk-s3-crt/source/S3CrtClient.cpp
@@ -510,7 +510,7 @@ int S3CrtClient::S3CrtRequestHeadersCallback(struct aws_s3_meta_request* meta_re
                                              int response_status, void* user_data) {
   AWS_UNREFERENCED_PARAM(meta_request);
   auto* userData = static_cast<S3CrtClient::CrtRequestCallbackUserData*>(user_data);
-  if (!userData || !userData->response || !userData->originalRequest) {
+  if (!userData || !userData->response || !userData->originalRequest || !headers) {
     return AWS_OP_ERR;
   }
 
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtSpecificOperations.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtSpecificOperations.vm
index 4cea67b9cdc..a6a0f973713 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtSpecificOperations.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtSpecificOperations.vm
@@ -21,7 +21,7 @@ int S3CrtClient::S3CrtRequestHeadersCallback(struct aws_s3_meta_request *meta_re
 {
   AWS_UNREFERENCED_PARAM(meta_request);
   auto *userData = static_cast<S3CrtClient::CrtRequestCallbackUserData*>(user_data);
-  if (!userData || !userData->response || !userData->originalRequest) {
+  if (!userData || !userData->response || !userData->originalRequest || !headers) {
     return AWS_OP_ERR;
   }
 
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/SmithyS3CrtSpecificOperations.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/SmithyS3CrtSpecificOperations.vm
index c59c4efd3a7..b6d8e676707 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/SmithyS3CrtSpecificOperations.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/SmithyS3CrtSpecificOperations.vm
@@ -21,7 +21,7 @@ int S3CrtClient::S3CrtRequestHeadersCallback(struct aws_s3_meta_request *meta_re
 {
   AWS_UNREFERENCED_PARAM(meta_request);
   auto *userData = static_cast<S3CrtClient::CrtRequestCallbackUserData*>(user_data);
-  if (!userData || !userData->response || !userData->originalRequest) {
+  if (!userData || !userData->response || !userData->originalRequest || !headers) {
     return AWS_OP_ERR;
   }