diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/QpackEncoder.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/QpackEncoder.java
index 98be0df83adb..66a8be1c46fb 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/QpackEncoder.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/QpackEncoder.java
@@ -156,7 +156,7 @@ public int getTableCapacity()
     }
 
     /**
-     * Set the capacity of the DynamicTable and send a instruction to set the capacity on the remote Decoder.
+     * Set the capacity of the DynamicTable and send an instruction to set the capacity on the remote Decoder.
      *
      * @param capacity the new capacity.
      */
@@ -166,9 +166,15 @@ public void setTableCapacity(int capacity)
         {
             if (capacity > getMaxTableCapacity())
                 throw new IllegalArgumentException("DynamicTable capacity exceeds max capacity");
-            _context.getDynamicTable().setCapacity(capacity);
-            _handler.onInstructions(List.of(new SetCapacityInstruction(capacity)));
-            notifyInstructionHandler();
+            int oldCapacity = _context.getDynamicTable().getCapacity();
+
+            // Only send the instruction if there was a change to the table capacity.
+            if (oldCapacity != capacity)
+            {
+                _context.getDynamicTable().setCapacity(capacity);
+                _handler.onInstructions(List.of(new SetCapacityInstruction(capacity)));
+                notifyInstructionHandler();
+            }
         }
     }
 
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/BlockedStreamsTest.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/BlockedStreamsTest.java
index c688faf85151..7708f8af2bf6 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/BlockedStreamsTest.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/BlockedStreamsTest.java
@@ -23,14 +23,17 @@
 import org.eclipse.jetty.http3.qpack.internal.instruction.LiteralNameEntryInstruction;
 import org.eclipse.jetty.http3.qpack.internal.instruction.SectionAcknowledgmentInstruction;
 import org.eclipse.jetty.http3.qpack.internal.instruction.SetCapacityInstruction;
+import org.eclipse.jetty.http3.qpack.util.QpackTestUtil;
+import org.eclipse.jetty.http3.qpack.util.TestDecoderHandler;
+import org.eclipse.jetty.http3.qpack.util.TestEncoderHandler;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.NanoTime;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import static org.eclipse.jetty.http3.qpack.QpackTestUtil.encode;
-import static org.eclipse.jetty.http3.qpack.QpackTestUtil.toBuffer;
-import static org.eclipse.jetty.http3.qpack.QpackTestUtil.toMetaData;
+import static org.eclipse.jetty.http3.qpack.util.QpackTestUtil.encode;
+import static org.eclipse.jetty.http3.qpack.util.QpackTestUtil.toBuffer;
+import static org.eclipse.jetty.http3.qpack.util.QpackTestUtil.toMetaData;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/DecoderInstructionParserTest.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/DecoderInstructionParserTest.java
index 3216ad7162c3..922c2f1f3b2d 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/DecoderInstructionParserTest.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/DecoderInstructionParserTest.java
@@ -20,6 +20,7 @@
 import org.eclipse.jetty.http3.qpack.internal.instruction.IndexedNameEntryInstruction;
 import org.eclipse.jetty.http3.qpack.internal.instruction.SetCapacityInstruction;
 import org.eclipse.jetty.http3.qpack.internal.parser.DecoderInstructionParser;
+import org.eclipse.jetty.http3.qpack.util.QpackTestUtil;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EncodeDecodeTest.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EncodeDecodeTest.java
index 5610f077d95e..ad9c8ae22b0f 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EncodeDecodeTest.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EncodeDecodeTest.java
@@ -27,6 +27,9 @@
 import org.eclipse.jetty.http3.qpack.internal.instruction.SetCapacityInstruction;
 import org.eclipse.jetty.http3.qpack.internal.parser.DecoderInstructionParser;
 import org.eclipse.jetty.http3.qpack.internal.parser.EncoderInstructionParser;
+import org.eclipse.jetty.http3.qpack.util.QpackTestUtil;
+import org.eclipse.jetty.http3.qpack.util.TestDecoderHandler;
+import org.eclipse.jetty.http3.qpack.util.TestEncoderHandler;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.NanoTime;
 import org.junit.jupiter.api.BeforeEach;
@@ -155,4 +158,32 @@ public void test() throws Exception
         assertThat(QpackTestUtil.toHexString(instruction), QpackTestUtil.equalsHex("4a63 7573 746f 6d2d 6b65 790c 6375 7374 6f6d 2d76 616c 7565"));
         _encoder.getInstructionHandler().onInsertCountIncrement(1);
     }
+
+    @Test
+    public void testEncoderSetCapacity()
+    {
+        _encoder.setMaxTableCapacity(1024 * 1024);
+
+        // Since capacity is already 0, this should not produce an instruction.
+        _encoder.setTableCapacity(0);
+        Instruction instruction = _encoderHandler.getInstruction();
+        assertNull(instruction);
+
+        // If we change the value of the table an instruction will be produced.
+        _encoder.setTableCapacity(1024);
+        instruction = _encoderHandler.getInstruction();
+        assertThat(instruction, instanceOf(SetCapacityInstruction.class));
+        assertThat(((SetCapacityInstruction)instruction).getCapacity(), is(1024));
+
+        // No instruction since size was already 1024.
+        _encoder.setTableCapacity(1024);
+        instruction = _encoderHandler.getInstruction();
+        assertNull(instruction);
+
+        // We can return the size back to 0 and an instruction is sent.
+        _encoder.setTableCapacity(0);
+        instruction = _encoderHandler.getInstruction();
+        assertThat(instruction, instanceOf(SetCapacityInstruction.class));
+        assertThat(((SetCapacityInstruction)instruction).getCapacity(), is(0));
+    }
 }
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EncoderInstructionParserTest.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EncoderInstructionParserTest.java
index 573fe33130dc..91673c5ec5ab 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EncoderInstructionParserTest.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EncoderInstructionParserTest.java
@@ -16,6 +16,7 @@
 import java.nio.ByteBuffer;
 
 import org.eclipse.jetty.http3.qpack.internal.parser.EncoderInstructionParser;
+import org.eclipse.jetty.http3.qpack.util.QpackTestUtil;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.StringUtil;
 import org.junit.jupiter.api.BeforeEach;
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EvictionTest.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EvictionTest.java
index b000d1e0633e..174c05c387da 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EvictionTest.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/EvictionTest.java
@@ -20,6 +20,8 @@
 import org.eclipse.jetty.http.HttpFields;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.http.MetaData;
+import org.eclipse.jetty.http3.qpack.util.TestDecoderHandler;
+import org.eclipse.jetty.http3.qpack.util.TestEncoderHandler;
 import org.eclipse.jetty.util.NanoTime;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/QpackDecoderTest.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/QpackDecoderTest.java
index a6b2c42348fc..7d096467d627 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/QpackDecoderTest.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/QpackDecoderTest.java
@@ -17,6 +17,7 @@
 
 import org.eclipse.jetty.http.MetaData;
 import org.eclipse.jetty.http3.qpack.internal.table.Entry;
+import org.eclipse.jetty.http3.qpack.util.TestDecoderHandler;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.NanoTime;
 import org.eclipse.jetty.util.StringUtil;
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/SectionAcknowledgmentTest.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/SectionAcknowledgmentTest.java
index 64a12489bb7a..4a7a3ae0d3a8 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/SectionAcknowledgmentTest.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/SectionAcknowledgmentTest.java
@@ -17,14 +17,16 @@
 
 import org.eclipse.jetty.http3.qpack.QpackException.SessionException;
 import org.eclipse.jetty.http3.qpack.internal.instruction.SectionAcknowledgmentInstruction;
+import org.eclipse.jetty.http3.qpack.util.TestDecoderHandler;
+import org.eclipse.jetty.http3.qpack.util.TestEncoderHandler;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.NanoTime;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import static org.eclipse.jetty.http3.qpack.QpackTestUtil.encode;
-import static org.eclipse.jetty.http3.qpack.QpackTestUtil.toBuffer;
-import static org.eclipse.jetty.http3.qpack.QpackTestUtil.toMetaData;
+import static org.eclipse.jetty.http3.qpack.util.QpackTestUtil.encode;
+import static org.eclipse.jetty.http3.qpack.util.QpackTestUtil.toBuffer;
+import static org.eclipse.jetty.http3.qpack.util.QpackTestUtil.toMetaData;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/QpackTestUtil.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/util/QpackTestUtil.java
similarity index 96%
rename from jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/QpackTestUtil.java
rename to jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/util/QpackTestUtil.java
index 827d73d12624..392cb7812b69 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/QpackTestUtil.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/util/QpackTestUtil.java
@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.util;
 
 import java.nio.ByteBuffer;
 import java.util.List;
@@ -21,6 +21,9 @@
 import org.eclipse.jetty.http.HttpFields;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.http.MetaData;
+import org.eclipse.jetty.http3.qpack.Instruction;
+import org.eclipse.jetty.http3.qpack.QpackEncoder;
+import org.eclipse.jetty.http3.qpack.QpackException;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.StringUtil;
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/TestDecoderHandler.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/util/TestDecoderHandler.java
similarity index 92%
rename from jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/TestDecoderHandler.java
rename to jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/util/TestDecoderHandler.java
index c5a7c2361e88..ff42ab51d560 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/TestDecoderHandler.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/util/TestDecoderHandler.java
@@ -11,13 +11,15 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.util;
 
 import java.nio.ByteBuffer;
 import java.util.LinkedList;
 import java.util.List;
 
 import org.eclipse.jetty.http.MetaData;
+import org.eclipse.jetty.http3.qpack.Instruction;
+import org.eclipse.jetty.http3.qpack.QpackDecoder;
 
 public class TestDecoderHandler implements QpackDecoder.Handler, Instruction.Handler
 {
diff --git a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/TestEncoderHandler.java b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/util/TestEncoderHandler.java
similarity index 93%
rename from jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/TestEncoderHandler.java
rename to jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/util/TestEncoderHandler.java
index fe5617697727..8dfc6e20eec0 100644
--- a/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/TestEncoderHandler.java
+++ b/jetty-core/jetty-http3/jetty-http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/util/TestEncoderHandler.java
@@ -11,12 +11,14 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.util;
 
 import java.nio.ByteBuffer;
 import java.util.LinkedList;
 import java.util.List;
 
+import org.eclipse.jetty.http3.qpack.Instruction;
+
 public class TestEncoderHandler implements Instruction.Handler
 {
     private final LinkedList<Instruction> _instructionList = new LinkedList<>();