Index: uspace/srv/hid/rfb/main.c
===================================================================
--- uspace/srv/hid/rfb/main.c	(revision bea947f408d47e1cbc0f0bf0321d45f2f00ad11a)
+++ uspace/srv/hid/rfb/main.c	(revision afcf7049d7f35c862988f3e47d752144e2c6aaac)
@@ -195,4 +195,8 @@
 	errno_t rc;
 
+	/* Check that we support all required flags */
+	if ((params->flags & ~bmpf_color_key) != 0)
+		return ENOTSUP;
+
 	rfbbm = calloc(1, sizeof(rfb_bitmap_t));
 	if (rfbbm == NULL)