diff --git a/jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/content/ContentSourceTransformer.java b/jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/content/ContentSourceTransformer.java
index f1e98eee312..9fefc147a08 100644
--- a/jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/content/ContentSourceTransformer.java
+++ b/jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/content/ContentSourceTransformer.java
@@ -16,6 +16,7 @@ package org.eclipse.jetty.io.content;
 import java.util.Objects;
 
 import org.eclipse.jetty.io.Content;
+import org.eclipse.jetty.util.thread.SerializedInvoker;
 
 /**
  * <p>This abstract {@link Content.Source} wraps another {@link Content.Source} and implementers need only
@@ -28,11 +29,12 @@ import org.eclipse.jetty.io.Content;
  */
 public abstract class ContentSourceTransformer implements Content.Source
 {
+    private final SerializedInvoker invoker = new SerializedInvoker();
     private final Content.Source rawSource;
     private Content.Chunk rawChunk;
     private Content.Chunk transformedChunk;
-    private boolean needsRawRead;
-    private Runnable demandCallback;
+    private volatile boolean needsRawRead;
+    private volatile Runnable demandCallback;
 
     public ContentSourceTransformer(Content.Source rawSource)
     {
@@ -79,7 +81,10 @@ public abstract class ContentSourceTransformer implements Content.Source
     public void demand(Runnable demandCallback)
     {
         this.demandCallback = Objects.requireNonNull(demandCallback);
-        rawSource.demand(this::onRawAvailable);
+        if (needsRawRead)
+            rawSource.demand(() -> invoker.run(this::invokeDemandCallback));
+        else
+            invoker.run(this::invokeDemandCallback);
     }
 
     @Override
@@ -88,11 +93,12 @@ public abstract class ContentSourceTransformer implements Content.Source
         rawSource.fail(failure);
     }
 
-    private void onRawAvailable()
+    private void invokeDemandCallback()
     {
         Runnable demandCallback = this.demandCallback;
         this.demandCallback = null;
-        runDemandCallback(demandCallback);
+        if (demandCallback != null)
+            runDemandCallback(demandCallback);
     }
 
     private void runDemandCallback(Runnable demandCallback)
diff --git a/jetty-core/jetty-io/src/test/java/org/eclipse/jetty/io/ContentSourceTransformerTest.java b/jetty-core/jetty-io/src/test/java/org/eclipse/jetty/io/ContentSourceTransformerTest.java
index a2d73229cdc..a09a0e53dd4 100644
--- a/jetty-core/jetty-io/src/test/java/org/eclipse/jetty/io/ContentSourceTransformerTest.java
+++ b/jetty-core/jetty-io/src/test/java/org/eclipse/jetty/io/ContentSourceTransformerTest.java
@@ -30,6 +30,8 @@ import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.empty;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertInstanceOf;
@@ -138,7 +140,54 @@ public class ContentSourceTransformerTest
             }
         });
 
-        assertTrue(expected.isEmpty());
+        assertThat(expected, empty());
+    }
+
+    @Test
+    public void testDemandFirstWithoutLoopStallAfterTwoExpectedChunks()
+    {
+        AsyncContent source = new AsyncContent();
+        source.write(Content.Chunk.from(UTF_8.encode("ONE NOOP two"), false), Callback.NOOP);
+        WordSplitLowCaseTransformer transformer = new WordSplitLowCaseTransformer(source);
+
+        AtomicBoolean reEnter = new AtomicBoolean();
+        Queue<String> expected = new ArrayDeque<>(List.of("one", "two"));
+        transformer.demand(new Runnable()
+        {
+            @Override
+            public void run()
+            {
+                if (!reEnter.compareAndSet(false, true))
+                    throw new IllegalStateException();
+
+                Content.Chunk chunk = transformer.read();
+                if (chunk != null)
+                    assertEquals(expected.poll(), UTF_8.decode(chunk.getByteBuffer()).toString());
+
+                if (chunk == null || !chunk.isLast())
+                    transformer.demand(this);
+
+                if (!reEnter.compareAndSet(true, false))
+                    throw new IllegalStateException();
+            }
+        });
+
+        assertThat(expected, empty());
+
+        expected.offer("three");
+        source.write(Content.Chunk.from(UTF_8.encode("three"), true), Callback.NOOP);
+        assertThat(expected, empty());
+
+        expected.offer("EOF");
+        transformer.demand(() ->
+        {
+            Content.Chunk chunk = transformer.read();
+            assertTrue(chunk.isLast());
+            assertFalse(chunk.hasRemaining());
+            expected.poll();
+        });
+
+        assertThat(expected, empty());
     }
 
     @Test