--- a/present/present_scmd.c	2022-02-08 09:38:39.322128250 +0100
+++ b/present/present_scmd.c	2022-02-08 09:40:30.205857503 +0100
@@ -167,6 +167,9 @@
 {
     if (!screen_priv->info)
         return NULL;
+        
+    if (!screen_priv->info->get_crtc)
+        return NULL;
 
     return (*screen_priv->info->get_crtc)(window);
 }
@@ -205,6 +208,9 @@
 
     if (!screen_priv->info)
         return;
+        
+    if (!screen_priv->info->flush)
+        return;
 
     (*screen_priv->info->flush) (window);
 }