diff --git a/backend/common.go b/backend/common.go
index 79bb7d20..951d4841 100644
--- a/backend/common.go
+++ b/backend/common.go
@@ -19,6 +19,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"hash"
 	"io"
 	"io/fs"
 	"net/url"
@@ -391,3 +392,14 @@ func MoveFile(source, destination string, perm os.FileMode) error {
 
 	return nil
 }
+
+// GenerateEtag generates a new quoted etag from the provided hash.Hash
+func GenerateEtag(h hash.Hash) string {
+	dataSum := h.Sum(nil)
+	return fmt.Sprintf("\"%s\"", hex.EncodeToString(dataSum[:]))
+}
+
+// AreEtagsSame compares 2 etags by ignoring quotes
+func AreEtagsSame(e1, e2 string) bool {
+	return strings.Trim(e1, `"`) == strings.Trim(e2, `"`)
+}
diff --git a/backend/posix/posix.go b/backend/posix/posix.go
index 66d379ee..4c66b45b 100644
--- a/backend/posix/posix.go
+++ b/backend/posix/posix.go
@@ -18,11 +18,9 @@ import (
 	"context"
 	"crypto/md5"
 	"crypto/sha256"
-	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"fmt"
-	"hash"
 	"io"
 	"io/fs"
 	"net/http"
@@ -95,7 +93,7 @@ const (
 	contentDispHdr      = "content-disposition"
 	cacheCtrlHdr        = "cache-control"
 	expiresHdr          = "expires"
-	emptyMD5            = "d41d8cd98f00b204e9800998ecf8427e"
+	emptyMD5            = "\"d41d8cd98f00b204e9800998ecf8427e\""
 	aclkey              = "acl"
 	ownershipkey        = "ownership"
 	etagkey             = "etag"
@@ -1472,7 +1470,7 @@ func (p *Posix) CompleteMultipartUpload(ctx context.Context, input *s3.CompleteM
 		if err != nil {
 			etag = ""
 		}
-		if parts[i].ETag == nil || !areEtagsSame(etag, *parts[i].ETag) {
+		if parts[i].ETag == nil || !backend.AreEtagsSame(etag, *parts[i].ETag) {
 			return res, "", s3err.GetAPIError(s3err.ErrInvalidPart)
 		}
 
@@ -2406,7 +2404,7 @@ func (p *Posix) UploadPart(ctx context.Context, input *s3.UploadPartInput) (*s3.
 		return nil, fmt.Errorf("write part data: %w", err)
 	}
 
-	etag := generateEtag(hash)
+	etag := backend.GenerateEtag(hash)
 	err = p.meta.StoreAttribute(f.File(), bucket, partPath, etagkey, []byte(etag))
 	if err != nil {
 		return nil, fmt.Errorf("set etag attr: %w", err)
@@ -2645,8 +2643,7 @@ func (p *Posix) UploadPartCopy(ctx context.Context, upi *s3.UploadPartCopyInput)
 		}
 	}
 
-	dataSum := hash.Sum(nil)
-	etag := hex.EncodeToString(dataSum)
+	etag := backend.GenerateEtag(hash)
 	err = p.meta.StoreAttribute(f.File(), *upi.Bucket, partPath, etagkey, []byte(etag))
 	if err != nil {
 		return s3response.CopyPartResult{}, fmt.Errorf("set etag attr: %w", err)
@@ -2855,7 +2852,7 @@ func (p *Posix) PutObject(ctx context.Context, po s3response.PutObjectInput) (s3
 		}
 	}
 
-	etag := generateEtag(hash)
+	etag := backend.GenerateEtag(hash)
 
 	// if the versioning is enabled, generate a new versionID for the object
 	var versionID string
@@ -5006,12 +5003,3 @@ func joinPathWithTrailer(paths ...string) string {
 	}
 	return joined
 }
-
-func generateEtag(h hash.Hash) string {
-	dataSum := h.Sum(nil)
-	return fmt.Sprintf("\"%s\"", hex.EncodeToString(dataSum[:]))
-}
-
-func areEtagsSame(e1, e2 string) bool {
-	return strings.Trim(e1, `"`) == strings.Trim(e2, `"`)
-}
diff --git a/backend/scoutfs/scoutfs.go b/backend/scoutfs/scoutfs.go
index a0930914..462cfc3f 100644
--- a/backend/scoutfs/scoutfs.go
+++ b/backend/scoutfs/scoutfs.go
@@ -287,7 +287,7 @@ func (s *ScoutFS) CompleteMultipartUpload(ctx context.Context, input *s3.Complet
 		if err != nil {
 			etag = ""
 		}
-		if parts[i].ETag == nil || !areEtagsSame(etag, *parts[i].ETag) {
+		if parts[i].ETag == nil || !backend.AreEtagsSame(etag, *parts[i].ETag) {
 			return res, "", s3err.GetAPIError(s3err.ErrInvalidPart)
 		}
 
@@ -1033,7 +1033,3 @@ func isNoAttr(err error) bool {
 	}
 	return false
 }
-
-func areEtagsSame(e1, e2 string) bool {
-	return strings.Trim(e1, `"`) == strings.Trim(e2, `"`)
-}