diff --git a/clientapi/routing/keys.go b/clientapi/routing/keys.go
index ba03a352..e2233642 100644
--- a/clientapi/routing/keys.go
+++ b/clientapi/routing/keys.go
@@ -38,7 +38,10 @@ func UploadKeys(req *http.Request, keyAPI api.KeyInternalAPI, device *userapi.De
 		return *resErr
 	}
 
-	uploadReq := &api.PerformUploadKeysRequest{}
+	uploadReq := &api.PerformUploadKeysRequest{
+		DeviceID: device.ID,
+		UserID:   device.UserID,
+	}
 	if r.DeviceKeys != nil {
 		uploadReq.DeviceKeys = []api.DeviceKeys{
 			{
diff --git a/keyserver/api/api.go b/keyserver/api/api.go
index 442af871..5cb287bc 100644
--- a/keyserver/api/api.go
+++ b/keyserver/api/api.go
@@ -108,6 +108,8 @@ type OneTimeKeysCount struct {
 
 // PerformUploadKeysRequest is the request to PerformUploadKeys
 type PerformUploadKeysRequest struct {
+	UserID      string // Required - User performing the request
+	DeviceID    string // Optional - Device performing the request, for fetching OTK count
 	DeviceKeys  []DeviceKeys
 	OneTimeKeys []OneTimeKeys
 	// OnlyDisplayNameUpdates should be `true` if ALL the DeviceKeys are present to update
diff --git a/keyserver/internal/internal.go b/keyserver/internal/internal.go
index 53afe0a6..f53a0761 100644
--- a/keyserver/internal/internal.go
+++ b/keyserver/internal/internal.go
@@ -513,6 +513,23 @@ func (a *KeyInternalAPI) uploadLocalDeviceKeys(ctx context.Context, req *api.Per
 }
 
 func (a *KeyInternalAPI) uploadOneTimeKeys(ctx context.Context, req *api.PerformUploadKeysRequest, res *api.PerformUploadKeysResponse) {
+	if req.UserID == "" {
+		res.Error = &api.KeyError{
+			Err: "user ID  missing",
+		}
+	}
+	if req.DeviceID != "" && len(req.OneTimeKeys) == 0 {
+		counts, err := a.DB.OneTimeKeysCount(ctx, req.UserID, req.DeviceID)
+		if err != nil {
+			res.Error = &api.KeyError{
+				Err: fmt.Sprintf("a.DB.OneTimeKeysCount: %s", err),
+			}
+		}
+		if counts != nil {
+			res.OneTimeKeyCounts = append(res.OneTimeKeyCounts, *counts)
+		}
+		return
+	}
 	for _, key := range req.OneTimeKeys {
 		// grab existing keys based on (user/device/algorithm/key ID)
 		keyIDsWithAlgorithms := make([]string, len(key.KeyJSON))
@@ -521,9 +538,9 @@ func (a *KeyInternalAPI) uploadOneTimeKeys(ctx context.Context, req *api.Perform
 			keyIDsWithAlgorithms[i] = keyIDWithAlgo
 			i++
 		}
-		existingKeys, err := a.DB.ExistingOneTimeKeys(ctx, key.UserID, key.DeviceID, keyIDsWithAlgorithms)
+		existingKeys, err := a.DB.ExistingOneTimeKeys(ctx, req.UserID, req.DeviceID, keyIDsWithAlgorithms)
 		if err != nil {
-			res.KeyError(key.UserID, key.DeviceID, &api.KeyError{
+			res.KeyError(req.UserID, req.DeviceID, &api.KeyError{
 				Err: "failed to query existing one-time keys: " + err.Error(),
 			})
 			continue
@@ -531,8 +548,8 @@ func (a *KeyInternalAPI) uploadOneTimeKeys(ctx context.Context, req *api.Perform
 		for keyIDWithAlgo := range existingKeys {
 			// if keys exist and the JSON doesn't match, error out as the key already exists
 			if !bytes.Equal(existingKeys[keyIDWithAlgo], key.KeyJSON[keyIDWithAlgo]) {
-				res.KeyError(key.UserID, key.DeviceID, &api.KeyError{
-					Err: fmt.Sprintf("%s device %s: algorithm / key ID %s one-time key already exists", key.UserID, key.DeviceID, keyIDWithAlgo),
+				res.KeyError(req.UserID, req.DeviceID, &api.KeyError{
+					Err: fmt.Sprintf("%s device %s: algorithm / key ID %s one-time key already exists", req.UserID, req.DeviceID, keyIDWithAlgo),
 				})
 				continue
 			}
@@ -540,8 +557,8 @@ func (a *KeyInternalAPI) uploadOneTimeKeys(ctx context.Context, req *api.Perform
 		// store one-time keys
 		counts, err := a.DB.StoreOneTimeKeys(ctx, key)
 		if err != nil {
-			res.KeyError(key.UserID, key.DeviceID, &api.KeyError{
-				Err: fmt.Sprintf("%s device %s : failed to store one-time keys: %s", key.UserID, key.DeviceID, err.Error()),
+			res.KeyError(req.UserID, req.DeviceID, &api.KeyError{
+				Err: fmt.Sprintf("%s device %s : failed to store one-time keys: %s", req.UserID, req.DeviceID, err.Error()),
 			})
 			continue
 		}
diff --git a/sytest-blacklist b/sytest-blacklist
index 601a3f70..b635c9f0 100644
--- a/sytest-blacklist
+++ b/sytest-blacklist
@@ -66,4 +66,7 @@ A prev_batch token from incremental sync can be used in the v1 messages API
 Forgotten room messages cannot be paginated
 
 # Blacklisted due to flakiness
-Can re-join room if re-invited
\ No newline at end of file
+Can re-join room if re-invited
+
+# Blacklisted due to flakiness after #1774
+Local device key changes get to remote servers with correct prev_id
\ No newline at end of file
diff --git a/sytest-whitelist b/sytest-whitelist
index d53fa899..1e4442a0 100644
--- a/sytest-whitelist
+++ b/sytest-whitelist
@@ -143,7 +143,6 @@ Local new device changes appear in v2 /sync
 Local update device changes appear in v2 /sync
 Get left notifs for other users in sync and /keys/changes when user leaves
 Local device key changes get to remote servers
-Local device key changes get to remote servers with correct prev_id
 Server correctly handles incoming m.device_list_update
 If remote user leaves room, changes device and rejoins we see update in sync
 If remote user leaves room, changes device and rejoins we see update in /keys/changes
diff --git a/userapi/internal/api.go b/userapi/internal/api.go
index d8af5433..4abf908d 100644
--- a/userapi/internal/api.go
+++ b/userapi/internal/api.go
@@ -161,6 +161,7 @@ func (a *UserInternalAPI) deviceListUpdate(userID string, deviceIDs []string) er
 
 	var uploadRes keyapi.PerformUploadKeysResponse
 	a.KeyAPI.PerformUploadKeys(context.Background(), &keyapi.PerformUploadKeysRequest{
+		UserID:     userID,
 		DeviceKeys: deviceKeys,
 	}, &uploadRes)
 	if uploadRes.Error != nil {
@@ -217,6 +218,7 @@ func (a *UserInternalAPI) PerformDeviceUpdate(ctx context.Context, req *api.Perf
 		// display name has changed: update the device key
 		var uploadRes keyapi.PerformUploadKeysResponse
 		a.KeyAPI.PerformUploadKeys(context.Background(), &keyapi.PerformUploadKeysRequest{
+			UserID: req.RequestingUserID,
 			DeviceKeys: []keyapi.DeviceKeys{
 				{
 					DeviceID:    dev.ID,