diff --git a/repos/ports/src/virtualbox6/include/fb.h b/repos/ports/src/virtualbox6/include/fb.h
index 6fba107e33..1ef22a3bb3 100644
--- a/repos/ports/src/virtualbox6/include/fb.h
+++ b/repos/ports/src/virtualbox6/include/fb.h
@@ -214,6 +214,7 @@ class Genodefb :
 			Lock();
 
 			if (_display_bitmap.isNull()) {
+				_clear_screen();
 				Unlock();
 				return S_OK;
 			}