diff --git a/FrOSCon26/examples/demo-uring.cpp b/FrOSCon26/examples/demo-uring.cpp
index 61177d4..220501d 100644
--- a/FrOSCon26/examples/demo-uring.cpp
+++ b/FrOSCon26/examples/demo-uring.cpp
@@ -203,6 +203,9 @@ UringVideoPlayer::addNextReadSubmissions (io_uring& uRing, int inputFD)
     {
       size_t srcOffset = calcSrcFrame (nextRead_);
       io_uring_sqe* readSubmission = io_uring_get_sqe (&uRing);
+      if (nullptr == readSubmission)
+        __FAIL ("URing slot allocation failed");
+
       io_uring_prep_read (readSubmission
                          ,inputFD
                          ,& buffer_[nextRead_ % RING_SIZ]
diff --git a/FrOSCon26/examples/egl-display.hpp b/FrOSCon26/examples/egl-display.hpp
index 435fcfe..941427c 100644
--- a/FrOSCon26/examples/egl-display.hpp
+++ b/FrOSCon26/examples/egl-display.hpp
@@ -45,7 +45,7 @@ class EglDisplay
     using Buffer = std::array<PIX, WIDTH*HEIGHT * 3 >;
 
     /**
-     * Interface retrieve pixel data for video frames to display.
+     * Interface: retrieve pixel data for video frames to display.
      * - this is a Glib::Dispatcher, and the attached slot shall be
      *   triggered whenever data for a new frame is available
      * - pixel data is accessed (threadsafe) by invoking #retrieveFrame()
@@ -85,7 +85,7 @@ class EglDisplay
     float scaleX_{1};
     float scaleY_{1};
 
-    /** Callback functor to access current pixel data */
+    /** Callback to retrieve pixel data */
     PixelFeed& pixelFeed_{};
 
     void openDisplay (Gtk::Window&);