diff --git a/api/handler/multipart_upload.go b/api/handler/multipart_upload.go
index 8a68fd9..c9ba0cb 100644
--- a/api/handler/multipart_upload.go
+++ b/api/handler/multipart_upload.go
@@ -104,10 +104,7 @@ func (h *handler) CreateMultipartUploadHandler(w http.ResponseWriter, r *http.Re
 	}
 
 	uploadID := uuid.New()
-	additional := []zap.Field{
-		zap.String("uploadID", uploadID.String()),
-		zap.String("Key", reqInfo.ObjectName),
-	}
+	additional := []zap.Field{zap.String("uploadID", uploadID.String())}
 
 	p := &layer.CreateMultipartParams{
 		Info: &layer.UploadInfoParams{
@@ -121,11 +118,11 @@ func (h *handler) CreateMultipartUploadHandler(w http.ResponseWriter, r *http.Re
 	if containsACLHeaders(r) {
 		key, err := h.bearerTokenIssuerKey(r.Context())
 		if err != nil {
-			h.logAndSendError(w, "couldn't get gate key", reqInfo, err)
+			h.logAndSendError(w, "couldn't get gate key", reqInfo, err, additional...)
 			return
 		}
 		if _, err = parseACLHeaders(r.Header, key); err != nil {
-			h.logAndSendError(w, "could not parse acl", reqInfo, err)
+			h.logAndSendError(w, "could not parse acl", reqInfo, err, additional...)
 			return
 		}
 		p.Data.ACLHeaders = formACLHeadersForMultipart(r.Header)
@@ -141,7 +138,7 @@ func (h *handler) CreateMultipartUploadHandler(w http.ResponseWriter, r *http.Re
 
 	p.Info.Encryption, err = formEncryptionParams(r)
 	if err != nil {
-		h.logAndSendError(w, "invalid sse headers", reqInfo, err)
+		h.logAndSendError(w, "invalid sse headers", reqInfo, err, additional...)
 		return
 	}
 
@@ -152,7 +149,7 @@ func (h *handler) CreateMultipartUploadHandler(w http.ResponseWriter, r *http.Re
 
 	p.CopiesNumbers, err = h.pickCopiesNumbers(p.Header, bktInfo.LocationConstraint)
 	if err != nil {
-		h.logAndSendError(w, "invalid copies number", reqInfo, err)
+		h.logAndSendError(w, "invalid copies number", reqInfo, err, additional...)
 		return
 	}
 
@@ -208,18 +205,19 @@ func (h *handler) UploadPartHandler(w http.ResponseWriter, r *http.Request) {
 	var (
 		queryValues = r.URL.Query()
 		uploadID    = queryValues.Get(uploadIDHeaderName)
-		additional  = []zap.Field{zap.String("uploadID", uploadID), zap.String("Key", reqInfo.ObjectName)}
+		partNumStr  = queryValues.Get(partNumberHeaderName)
+		additional  = []zap.Field{zap.String("uploadID", uploadID), zap.String("partNumber", partNumStr)}
 	)
 
-	partNumber, err := strconv.Atoi(queryValues.Get(partNumberHeaderName))
+	partNumber, err := strconv.Atoi(partNumStr)
 	if err != nil || partNumber < layer.UploadMinPartNumber || partNumber > layer.UploadMaxPartNumber {
-		h.logAndSendError(w, "invalid part number", reqInfo, errors.GetAPIError(errors.ErrInvalidPartNumber))
+		h.logAndSendError(w, "invalid part number", reqInfo, errors.GetAPIError(errors.ErrInvalidPartNumber), additional...)
 		return
 	}
 
 	body, err := h.getBodyReader(r)
 	if err != nil {
-		h.logAndSendError(w, "failed to get body reader", reqInfo, err)
+		h.logAndSendError(w, "failed to get body reader", reqInfo, err, additional...)
 		return
 	}
 
@@ -241,7 +239,7 @@ func (h *handler) UploadPartHandler(w http.ResponseWriter, r *http.Request) {
 
 	p.Info.Encryption, err = formEncryptionParams(r)
 	if err != nil {
-		h.logAndSendError(w, "invalid sse headers", reqInfo, err)
+		h.logAndSendError(w, "invalid sse headers", reqInfo, err, additional...)
 		return
 	}
 
@@ -266,12 +264,13 @@ func (h *handler) UploadPartCopy(w http.ResponseWriter, r *http.Request) {
 		reqInfo     = middleware.GetReqInfo(ctx)
 		queryValues = reqInfo.URL.Query()
 		uploadID    = queryValues.Get(uploadIDHeaderName)
-		additional  = []zap.Field{zap.String("uploadID", uploadID), zap.String("Key", reqInfo.ObjectName)}
+		partNumStr  = queryValues.Get(partNumberHeaderName)
+		additional  = []zap.Field{zap.String("uploadID", uploadID), zap.String("partNumber", partNumStr)}
 	)
 
-	partNumber, err := strconv.Atoi(queryValues.Get(partNumberHeaderName))
+	partNumber, err := strconv.Atoi(partNumStr)
 	if err != nil || partNumber < layer.UploadMinPartNumber || partNumber > layer.UploadMaxPartNumber {
-		h.logAndSendError(w, "invalid part number", reqInfo, errors.GetAPIError(errors.ErrInvalidPartNumber))
+		h.logAndSendError(w, "invalid part number", reqInfo, errors.GetAPIError(errors.ErrInvalidPartNumber), additional...)
 		return
 	}
 
@@ -282,7 +281,7 @@ func (h *handler) UploadPartCopy(w http.ResponseWriter, r *http.Request) {
 	}
 	srcBucket, srcObject, err := path2BucketObject(src)
 	if err != nil {
-		h.logAndSendError(w, "invalid source copy", reqInfo, err)
+		h.logAndSendError(w, "invalid source copy", reqInfo, err, additional...)
 		return
 	}
 
@@ -295,13 +294,13 @@ func (h *handler) UploadPartCopy(w http.ResponseWriter, r *http.Request) {
 
 	srcBktInfo, err := h.getBucketAndCheckOwner(r, srcBucket, api.AmzSourceExpectedBucketOwner)
 	if err != nil {
-		h.logAndSendError(w, "could not get source bucket info", reqInfo, err)
+		h.logAndSendError(w, "could not get source bucket info", reqInfo, err, additional...)
 		return
 	}
 
 	bktInfo, err := h.getBucketAndCheckOwner(r, reqInfo.BucketName)
 	if err != nil {
-		h.logAndSendError(w, "could not get target bucket info", reqInfo, err)
+		h.logAndSendError(w, "could not get target bucket info", reqInfo, err, additional...)
 		return
 	}
 
@@ -350,12 +349,12 @@ func (h *handler) UploadPartCopy(w http.ResponseWriter, r *http.Request) {
 
 	p.Info.Encryption, err = formEncryptionParams(r)
 	if err != nil {
-		h.logAndSendError(w, "invalid sse headers", reqInfo, err)
+		h.logAndSendError(w, "invalid sse headers", reqInfo, err, additional...)
 		return
 	}
 
 	if err = p.Info.Encryption.MatchObjectEncryption(layer.FormEncryptionInfo(srcInfo.Headers)); err != nil {
-		h.logAndSendError(w, "encryption doesn't match object", reqInfo, errors.GetAPIError(errors.ErrBadRequest), zap.Error(err))
+		h.logAndSendError(w, "encryption doesn't match object", reqInfo, fmt.Errorf("%w: %s", errors.GetAPIError(errors.ErrBadRequest), err), additional...)
 		return
 	}
 
@@ -375,7 +374,7 @@ func (h *handler) UploadPartCopy(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err = middleware.EncodeToResponse(w, response); err != nil {
-		h.logAndSendError(w, "something went wrong", reqInfo, err)
+		h.logAndSendError(w, "something went wrong", reqInfo, err, additional...)
 	}
 }
 
@@ -395,7 +394,7 @@ func (h *handler) CompleteMultipartUploadHandler(w http.ResponseWriter, r *http.
 			Bkt:      bktInfo,
 			Key:      reqInfo.ObjectName,
 		}
-		additional = []zap.Field{zap.String("uploadID", uploadID), zap.String("Key", reqInfo.ObjectName)}
+		additional = []zap.Field{zap.String("uploadID", uploadID)}
 	)
 
 	reqBody := new(CompleteMultipartUpload)
@@ -451,7 +450,7 @@ func (h *handler) CompleteMultipartUploadHandler(w http.ResponseWriter, r *http.
 	// space XML writer to keep connection with the client.
 
 	if err = responseWriter(w, response); err != nil {
-		errLogger(w, "something went wrong", reqInfo, err)
+		errLogger(w, "something went wrong", reqInfo, err, additional...)
 	}
 }