diff --git a/src/HTTPServer/browser-display.jl b/src/HTTPServer/browser-display.jl
index 57b323ab..8b9ac6fd 100644
--- a/src/HTTPServer/browser-display.jl
+++ b/src/HTTPServer/browser-display.jl
@@ -81,7 +81,13 @@ function Base.display(display::BrowserDisplay, app::App)
             if success
                 handler.session.status = Bonito.DISPLAYED
                 # if open_browser, we need to let the caller wait!
-                wait_for_ready(handler.session)
+                wait_for() do
+                    session = handler.session # can change inbetween
+                    if !isnothing(session.init_error[])
+                        throw(session.init_error[])
+                    end
+                    return isready(session)
+                end
                 wait_for_ready(app)
             end
         end
diff --git a/src/serialization/protocol.jl b/src/serialization/protocol.jl
index 0205e073..d3307bbd 100644
--- a/src/serialization/protocol.jl
+++ b/src/serialization/protocol.jl
@@ -19,9 +19,6 @@ Handles the incoming websocket messages from the frontend.
 Messages are expected to be gzip compressed and packed via MsgPack.
 """
 function process_message(session::Session, bytes::AbstractVector{UInt8})
-    if session.threadid != Threads.threadid()
-        error("process_message should only be called from the same thread as the session")
-    end
     if isempty(bytes)
         @warn "empty message received from frontend"
         return
diff --git a/src/session.jl b/src/session.jl
index 7c6f8640..98fcbd25 100644
--- a/src/session.jl
+++ b/src/session.jl
@@ -24,9 +24,6 @@ function wait_for_ready(session::Session; timeout=100)
         return :success
     end
     session.status == CLOSED && return nothing
-    if session.status !== DISPLAYED
-        error("Session got not displayed yet, so waiting for it to become ready is futile. Status: $(session.status)")
-    end
     return wait_for(timeout=timeout) do
         if !isnothing(session.init_error[])
             throw(session.init_error[])