diff --git a/internal/grpc/services/usershareprovider/usershareprovider.go b/internal/grpc/services/usershareprovider/usershareprovider.go
index c52caad51b..2c1cae656c 100644
--- a/internal/grpc/services/usershareprovider/usershareprovider.go
+++ b/internal/grpc/services/usershareprovider/usershareprovider.go
@@ -506,24 +506,6 @@ func (s *service) GetReceivedShare(ctx context.Context, req *collaboration.GetRe
 }
 
 func (s *service) UpdateReceivedShare(ctx context.Context, req *collaboration.UpdateReceivedShareRequest) (*collaboration.UpdateReceivedShareResponse, error) {
-	if req.GetShare() == nil {
-		return &collaboration.UpdateReceivedShareResponse{
-			Status: status.NewInvalid(ctx, "updating requires a received share object"),
-		}, nil
-	}
-
-	if req.GetShare().GetShare() == nil {
-		return &collaboration.UpdateReceivedShareResponse{
-			Status: status.NewInvalid(ctx, "share missing"),
-		}, nil
-	}
-
-	if req.GetShare().GetShare().GetId() == nil {
-		return &collaboration.UpdateReceivedShareResponse{
-			Status: status.NewInvalid(ctx, "share id missing"),
-		}, nil
-	}
-
 	if req.GetShare().GetShare().GetId().GetOpaqueId() == "" {
 		return &collaboration.UpdateReceivedShareResponse{
 			Status: status.NewInvalid(ctx, "share id empty"),
@@ -531,74 +513,23 @@ func (s *service) UpdateReceivedShare(ctx context.Context, req *collaboration.Up
 	}
 
 	isStateTransitionShareAccepted := slices.Contains(req.GetUpdateMask().GetPaths(), _fieldMaskPathState) && req.GetShare().GetState() == collaboration.ShareState_SHARE_STATE_ACCEPTED
-	if isStateTransitionShareAccepted {
+	isMountPointSet := slices.Contains(req.GetUpdateMask().GetPaths(), _fieldMaskPathMountPoint) && req.GetShare().GetMountPoint().GetPath() != ""
+	// we calculate a valid mountpoint only if the share should be accepted and the mount point is not set explicitly
+	if isStateTransitionShareAccepted && !isMountPointSet {
 		gatewayClient, err := s.gatewaySelector.Next()
 		if err != nil {
 			return nil, err
 		}
 
-		receivedShare, err := gatewayClient.GetReceivedShare(ctx, &collaboration.GetReceivedShareRequest{
-			Ref: &collaboration.ShareReference{
-				Spec: &collaboration.ShareReference_Id{
-					Id: req.GetShare().GetShare().GetId(),
-				},
-			},
-		})
-		switch {
-		case err != nil:
-			fallthrough
-		case receivedShare.GetStatus().GetCode() != rpc.Code_CODE_OK:
-			return &collaboration.UpdateReceivedShareResponse{
-				Status: receivedShare.GetStatus(),
-			}, err
-		}
-
-		resourceStat, err := gatewayClient.Stat(ctx, &provider.StatRequest{
-			Ref: &provider.Reference{
-				ResourceId: receivedShare.GetShare().GetShare().GetResourceId(),
-			},
-		})
+		s, err := setReceivedShareMountPoint(ctx, gatewayClient, req)
 		switch {
 		case err != nil:
 			fallthrough
-		case resourceStat.GetStatus().GetCode() != rpc.Code_CODE_OK:
+		case s.GetCode() != rpc.Code_CODE_OK:
 			return &collaboration.UpdateReceivedShareResponse{
-				Status: resourceStat.GetStatus(),
+				Status: s,
 			}, err
 		}
-
-		// handle mount point related updates
-		{
-			// find a suitable mount point
-			var requestedMountpoint string
-			switch {
-			case slices.Contains(req.GetUpdateMask().GetPaths(), _fieldMaskPathMountPoint) && req.GetShare().GetMountPoint().GetPath() != "":
-				requestedMountpoint = req.GetShare().GetMountPoint().GetPath()
-			case receivedShare.GetShare().GetMountPoint().GetPath() != "":
-				requestedMountpoint = receivedShare.GetShare().GetMountPoint().GetPath()
-			default:
-				requestedMountpoint = resourceStat.GetInfo().GetName()
-			}
-
-			// check if the requested mount point is available and if not, find a suitable one
-			availableMountpoint, err := GetAvailableMountpoint(ctx, gatewayClient,
-				resourceStat.GetInfo().GetId(),
-				requestedMountpoint,
-			)
-			if err != nil {
-				return &collaboration.UpdateReceivedShareResponse{
-					Status: status.NewInternal(ctx, err.Error()),
-				}, nil
-			}
-
-			if !slices.Contains(req.GetUpdateMask().GetPaths(), _fieldMaskPathMountPoint) {
-				req.GetUpdateMask().Paths = append(req.GetUpdateMask().GetPaths(), _fieldMaskPathMountPoint)
-			}
-
-			req.GetShare().MountPoint = &provider.Reference{
-				Path: availableMountpoint,
-			}
-		}
 	}
 
 	var uid userpb.UserId
@@ -627,7 +558,6 @@ func GetAvailableMountpoint(ctx context.Context, gwc gateway.GatewayAPIClient, i
 		return "", err
 	}
 
-	// we need to sort the received shares by mount point in order to make things easier to evaluate.
 	base := filepath.Clean(name)
 	mount := base
 	existingMountpoint := ""
@@ -670,11 +600,7 @@ func GetAvailableMountpoint(ctx context.Context, gwc gateway.GatewayAPIClient, i
 		for i := 1; i <= len(mountedShares)+1; i++ {
 			ext := filepath.Ext(base)
 			name := strings.TrimSuffix(base, ext)
-			// be smart about .tar.(gz|bz) files
-			if strings.HasSuffix(name, ".tar") {
-				name = strings.TrimSuffix(name, ".tar")
-				ext = ".tar" + ext
-			}
+
 			mount = name + " (" + strconv.Itoa(i) + ")" + ext
 			if !slices.Contains(mountedShares, mount) {
 				return mount, nil
@@ -684,3 +610,57 @@ func GetAvailableMountpoint(ctx context.Context, gwc gateway.GatewayAPIClient, i
 
 	return mount, nil
 }
+
+func setReceivedShareMountPoint(ctx context.Context, gwc gateway.GatewayAPIClient, req *collaboration.UpdateReceivedShareRequest) (*rpc.Status, error) {
+	receivedShare, err := gwc.GetReceivedShare(ctx, &collaboration.GetReceivedShareRequest{
+		Ref: &collaboration.ShareReference{
+			Spec: &collaboration.ShareReference_Id{
+				Id: req.GetShare().GetShare().GetId(),
+			},
+		},
+	})
+	switch {
+	case err != nil:
+		fallthrough
+	case receivedShare.GetStatus().GetCode() != rpc.Code_CODE_OK:
+		return receivedShare.GetStatus(), err
+	}
+
+	if receivedShare.GetShare().GetMountPoint().GetPath() != "" {
+		return status.NewOK(ctx), nil
+	}
+
+	resourceStat, err := gwc.Stat(ctx, &provider.StatRequest{
+		Ref: &provider.Reference{
+			ResourceId: receivedShare.GetShare().GetShare().GetResourceId(),
+		},
+	})
+	switch {
+	case err != nil:
+		fallthrough
+	case resourceStat.GetStatus().GetCode() != rpc.Code_CODE_OK:
+		return resourceStat.GetStatus(), err
+	}
+
+	// handle mount point related updates
+	{
+		// check if the requested mount point is available and if not, find a suitable one
+		availableMountpoint, err := GetAvailableMountpoint(ctx, gwc,
+			resourceStat.GetInfo().GetId(),
+			resourceStat.GetInfo().GetName(),
+		)
+		if err != nil {
+			return status.NewInternal(ctx, err.Error()), nil
+		}
+
+		if !slices.Contains(req.GetUpdateMask().GetPaths(), _fieldMaskPathMountPoint) {
+			req.GetUpdateMask().Paths = append(req.GetUpdateMask().GetPaths(), _fieldMaskPathMountPoint)
+		}
+
+		req.GetShare().MountPoint = &provider.Reference{
+			Path: availableMountpoint,
+		}
+	}
+
+	return status.NewOK(ctx), nil
+}
diff --git a/internal/grpc/services/usershareprovider/usershareprovider_test.go b/internal/grpc/services/usershareprovider/usershareprovider_test.go
index ba4ccf8210..9adcbef778 100644
--- a/internal/grpc/services/usershareprovider/usershareprovider_test.go
+++ b/internal/grpc/services/usershareprovider/usershareprovider_test.go
@@ -141,30 +141,6 @@ var _ = Describe("user share provider service", func() {
 				Expect(res.GetStatus().GetCode()).To(Equal(expectedStatus.GetCode()))
 				Expect(res.GetStatus().GetMessage()).To(ContainSubstring(expectedStatus.GetMessage()))
 			},
-			Entry(
-				"no received share",
-				&collaborationpb.UpdateReceivedShareRequest{},
-				status.NewInvalid(ctx, "updating requires"),
-				nil,
-			),
-			Entry(
-				"no share",
-				&collaborationpb.UpdateReceivedShareRequest{
-					Share: &collaborationpb.ReceivedShare{},
-				},
-				status.NewInvalid(ctx, "share missing"),
-				nil,
-			),
-			Entry(
-				"no share id",
-				&collaborationpb.UpdateReceivedShareRequest{
-					Share: &collaborationpb.ReceivedShare{
-						Share: &collaborationpb.Share{},
-					},
-				},
-				status.NewInvalid(ctx, "share id missing"),
-				nil,
-			),
 			Entry(
 				"no share opaque id",
 				&collaborationpb.UpdateReceivedShareRequest{