diff --git a/jetty-core/jetty-http3/jetty-http3-common/src/main/java/org/eclipse/jetty/http3/MessageFlusher.java b/jetty-core/jetty-http3/jetty-http3-common/src/main/java/org/eclipse/jetty/http3/MessageFlusher.java
index a1192c02a3a9..f450bfaf0ec2 100644
--- a/jetty-core/jetty-http3/jetty-http3-common/src/main/java/org/eclipse/jetty/http3/MessageFlusher.java
+++ b/jetty-core/jetty-http3/jetty-http3-common/src/main/java/org/eclipse/jetty/http3/MessageFlusher.java
@@ -75,7 +75,7 @@ protected Action process()
             return Action.SCHEDULED;
         }
 
-        int generated = generator.generate(accumulator, entry.endPoint.getStreamId(), frame, this::failed);
+        int generated = generator.generate(accumulator, entry.endPoint.getStreamId(), frame, this::onGenerateFailure);
         if (generated < 0)
             return Action.SCHEDULED;
 
@@ -88,35 +88,48 @@ protected Action process()
         return Action.SCHEDULED;
     }
 
-    // TODO this should be onSuccess()
-    @Override
-    public void succeeded()
+    private void onGenerateFailure(Throwable cause)
     {
         if (LOG.isDebugEnabled())
-            LOG.debug("succeeded to write {} on {}", entry, this);
+            LOG.debug("failed to generate {} on {}", entry, this, cause);
 
         accumulator.release();
 
-        entry.callback.succeeded();
+        entry.callback.failed(cause);
         entry = null;
 
-        super.succeeded();
+        // Continue the iteration.
+        succeeded();
     }
 
     @Override
-    public void failed(Throwable x)
+    protected void onSuccess()
     {
         if (LOG.isDebugEnabled())
-            LOG.debug("failed to write {} on {}", entry, this, x);
+            LOG.debug("succeeded to write {} on {}", entry, this);
 
         accumulator.release();
 
-        entry.callback.failed(x);
-        entry = null;
+        if (entry != null)
+        {
+            entry.callback.succeeded();
+            entry = null;
+        }
+    }
 
-        // Continue the iteration.
-        // TODO this is pure evil!
-        super.succeeded();
+    @Override
+    protected void onCompleteFailure(Throwable cause)
+    {
+        if (LOG.isDebugEnabled())
+            LOG.debug("failed to write {} on {}", entry, this, cause);
+
+        accumulator.release();
+
+        if (entry != null)
+        {
+            entry.callback.failed(cause);
+            entry = null;
+        }
     }
 
     @Override
diff --git a/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/IteratingCallback.java b/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/IteratingCallback.java
index 76d3bff375c0..6fc58187dbb7 100644
--- a/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/IteratingCallback.java
+++ b/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/IteratingCallback.java
@@ -356,7 +356,7 @@ else if (notifyCompleteFailure != null)
      * to call {@code super.succeeded()}.
      */
     @Override
-    public void succeeded()
+    public final void succeeded()
     {
         boolean process = false;
         try (AutoLock ignored = _lock.lock())
@@ -409,7 +409,7 @@ public void succeeded()
      * @see #isFailed()
      */
     @Override
-    public void failed(Throwable x)
+    public final void failed(Throwable x)
     {
         boolean failure = false;
         try (AutoLock ignored = _lock.lock())