diff --git a/backend/posix/posix.go b/backend/posix/posix.go
index 076e0c6f..6ba05731 100644
--- a/backend/posix/posix.go
+++ b/backend/posix/posix.go
@@ -2668,6 +2668,10 @@ func (p *Posix) PutObject(ctx context.Context, po s3response.PutObjectInput) (s3
 	if po.Key == nil {
 		return s3response.PutObjectOutput{}, s3err.GetAPIError(s3err.ErrNoSuchKey)
 	}
+	// Override the checksum algorithm with default: CRC64NVME
+	if po.ChecksumAlgorithm == "" {
+		po.ChecksumAlgorithm = types.ChecksumAlgorithmCrc64nvme
+	}
 	_, err := os.Stat(*po.Bucket)
 	if errors.Is(err, fs.ErrNotExist) {
 		return s3response.PutObjectOutput{}, s3err.GetAPIError(s3err.ErrNoSuchBucket)
diff --git a/tests/integration/group-tests.go b/tests/integration/group-tests.go
index f7c7a76a..921d37f5 100644
--- a/tests/integration/group-tests.go
+++ b/tests/integration/group-tests.go
@@ -148,6 +148,7 @@ func TestPutObject(s *S3Conf) {
 		PutObject_multiple_checksum_headers(s)
 		PutObject_invalid_checksum_header(s)
 		PutObject_incorrect_checksums(s)
+		PutObject_default_checksum(s)
 		PutObject_checksums_success(s)
 	}
 	PutObject_success(s)
@@ -811,6 +812,7 @@ func GetIntTests() IntTests {
 		"PutObject_multiple_checksum_headers":                                     PutObject_multiple_checksum_headers,
 		"PutObject_invalid_checksum_header":                                       PutObject_invalid_checksum_header,
 		"PutObject_incorrect_checksums":                                           PutObject_incorrect_checksums,
+		"PutObject_default_checksum":                                              PutObject_default_checksum,
 		"PutObject_checksums_success":                                             PutObject_checksums_success,
 		"PresignedAuth_Put_GetObject_with_data":                                   PresignedAuth_Put_GetObject_with_data,
 		"PresignedAuth_Put_GetObject_with_UTF8_chars":                             PresignedAuth_Put_GetObject_with_UTF8_chars,
diff --git a/tests/integration/tests.go b/tests/integration/tests.go
index ef79d28c..d4568853 100644
--- a/tests/integration/tests.go
+++ b/tests/integration/tests.go
@@ -31,6 +31,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/aws/aws-sdk-go-v2/aws"
 	"github.com/aws/aws-sdk-go-v2/service/s3"
 	"github.com/aws/aws-sdk-go-v2/service/s3/types"
 	"github.com/versity/versitygw/s3err"
@@ -3139,6 +3140,46 @@ func PutObject_incorrect_checksums(s *S3Conf) error {
 	})
 }
 
+func PutObject_default_checksum(s *S3Conf) error {
+	testName := "PutObject_default_checksum"
+	return actionHandler(s, testName, func(_ *s3.Client, bucket string) error {
+		customClient := s3.NewFromConfig(s.Config(), func(o *s3.Options) {
+			o.RequestChecksumCalculation = aws.RequestChecksumCalculationUnset
+		})
+
+		obj := "my-obj"
+
+		out, err := putObjectWithData(100, &s3.PutObjectInput{
+			Bucket: &bucket,
+			Key:    &obj,
+		}, customClient)
+		if err != nil {
+			return err
+		}
+
+		if out.res.ChecksumCRC64NVME == nil {
+			return fmt.Errorf("expected non nil default crc64nvme checksum")
+		}
+
+		ctx, cancel := context.WithTimeout(context.Background(), shortTimeout)
+		res, err := customClient.HeadObject(ctx, &s3.HeadObjectInput{
+			Bucket:       &bucket,
+			Key:          &obj,
+			ChecksumMode: types.ChecksumModeEnabled,
+		})
+		cancel()
+		if err != nil {
+			return err
+		}
+
+		if getString(res.ChecksumCRC64NVME) != getString(out.res.ChecksumCRC64NVME) {
+			return fmt.Errorf("expected the object crc64nvme checksum to be %v, instead got %v", getString(res.ChecksumCRC64NVME), getString(out.res.ChecksumCRC64NVME))
+		}
+
+		return nil
+	})
+}
+
 func PutObject_checksums_success(s *S3Conf) error {
 	testName := "PutObject_checksums_success"
 	return actionHandler(s, testName, func(s3client *s3.Client, bucket string) error {