diff --git a/libfreerdp/core/update.c b/libfreerdp/core/update.c
index 197c6df31..aa540f93f 100644
--- a/libfreerdp/core/update.c
+++ b/libfreerdp/core/update.c
@@ -517,6 +517,12 @@ static BOOL update_check_flush(rdpContext* context, int size)
 
 	s = update->us;
 
+	if (!update->us)
+	{
+		update->BeginPaint(context);
+		return FALSE;
+	}
+
 	if (Stream_GetPosition(s) + size + 256 >= settings->MultifragMaxRequestSize)
 	{
 		update_flush(context);
diff --git a/winpr/libwinpr/synch/wait.c b/winpr/libwinpr/synch/wait.c
index 8060aa8ed..d687e7c55 100644
--- a/winpr/libwinpr/synch/wait.c
+++ b/winpr/libwinpr/synch/wait.c
@@ -62,13 +62,16 @@ DWORD WaitForSingleObject(HANDLE hHandle, DWORD dwMilliseconds)
 
 		thread = (WINPR_THREAD*) Object;
 
-		status = pthread_join(thread->thread, &thread_status);
+		if (thread->started)
+		{
+			status = pthread_join(thread->thread, &thread_status);
 
-		if (status != 0)
-			fprintf(stderr, "WaitForSingleObject: pthread_join failure: %d\n", status);
+			if (status != 0)
+				fprintf(stderr, "WaitForSingleObject: pthread_join failure: %d\n", status);
 
-		if (thread_status)
-			thread->dwExitCode = ((DWORD) (size_t) thread_status);
+			if (thread_status)
+				thread->dwExitCode = ((DWORD) (size_t) thread_status);
+		}
 	}
 	else if (Type == HANDLE_TYPE_MUTEX)
 	{