diff --git a/syncapi/sync/requestpool.go b/syncapi/sync/requestpool.go
index 30c490df0..fdf46cdde 100644
--- a/syncapi/sync/requestpool.go
+++ b/syncapi/sync/requestpool.go
@@ -253,9 +253,12 @@ func (rp *RequestPool) OnIncomingSyncRequest(req *http.Request, device *userapi.
 			// We should always try to include OTKs in sync responses, otherwise clients might upload keys
 			// even if that's not required. See also:
 			// https://github.com/matrix-org/synapse/blob/29f06704b8871a44926f7c99e73cf4a978fb8e81/synapse/rest/client/sync.py#L276-L281
-			err = internal.DeviceOTKCounts(syncReq.Context, rp.keyAPI, syncReq.Device.UserID, syncReq.Device.ID, syncReq.Response)
-			if err != nil {
-				syncReq.Log.WithError(err).Error("failed to get OTK counts")
+			// Only try to get OTKs if the context isn't already done.
+			if syncReq.Context.Err() == nil {
+				err = internal.DeviceOTKCounts(syncReq.Context, rp.keyAPI, syncReq.Device.UserID, syncReq.Device.ID, syncReq.Response)
+				if err != nil && err != context.Canceled {
+					syncReq.Log.WithError(err).Warn("failed to get OTK counts")
+				}
 			}
 			return util.JSONResponse{
 				Code: http.StatusOK,