diff --git a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/DataGenerateParseTest.java b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/DataGenerateParseTest.java
index dd7f83760d8..2db99624324 100644
--- a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/DataGenerateParseTest.java
+++ b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/DataGenerateParseTest.java
@@ -130,18 +130,23 @@ public class DataGenerateParseTest
             }
         }, 4096, 8192);
 
-        ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
-        ByteBuffer data = ByteBuffer.wrap(largeContent);
-        generator.generateData(lease, 13, data.slice(), true, data.remaining());
-
-        for (ByteBuffer buffer : lease.getByteBuffers())
+        // Iterate a few times to be sure generator and parser are properly reset.
+        for (int i = 0; i < 2; ++i)
         {
-            while (buffer.hasRemaining())
-            {
-                parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
-            }
-        }
+            ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
+            ByteBuffer data = ByteBuffer.wrap(largeContent);
+            generator.generateData(lease, 13, data.slice(), true, data.remaining());
 
-        Assert.assertEquals(largeContent.length, frames.size());
+            frames.clear();
+            for (ByteBuffer buffer : lease.getByteBuffers())
+            {
+                while (buffer.hasRemaining())
+                {
+                    parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
+                }
+            }
+
+            Assert.assertEquals(largeContent.length, frames.size());
+        }
     }
 }
diff --git a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/GoAwayGenerateParseTest.java b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/GoAwayGenerateParseTest.java
index b53225a36ec..a51874170e5 100644
--- a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/GoAwayGenerateParseTest.java
+++ b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/GoAwayGenerateParseTest.java
@@ -96,21 +96,26 @@ public class GoAwayGenerateParseTest
         byte[] payload = new byte[16];
         new Random().nextBytes(payload);
 
-        ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
-        generator.generateGoAway(lease, lastStreamId, error, payload);
-
-        for (ByteBuffer buffer : lease.getByteBuffers())
+        // Iterate a few times to be sure generator and parser are properly reset.
+        for (int i = 0; i < 2; ++i)
         {
-            while (buffer.hasRemaining())
-            {
-                parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
-            }
-        }
+            ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
+            generator.generateGoAway(lease, lastStreamId, error, payload);
 
-        Assert.assertEquals(1, frames.size());
-        GoAwayFrame frame = frames.get(0);
-        Assert.assertEquals(lastStreamId, frame.getLastStreamId());
-        Assert.assertEquals(error, frame.getError());
-        Assert.assertArrayEquals(payload, frame.getPayload());
+            frames.clear();
+            for (ByteBuffer buffer : lease.getByteBuffers())
+            {
+                while (buffer.hasRemaining())
+                {
+                    parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
+                }
+            }
+
+            Assert.assertEquals(1, frames.size());
+            GoAwayFrame frame = frames.get(0);
+            Assert.assertEquals(lastStreamId, frame.getLastStreamId());
+            Assert.assertEquals(error, frame.getError());
+            Assert.assertArrayEquals(payload, frame.getPayload());
+        }
     }
 }
diff --git a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PingGenerateParseTest.java b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PingGenerateParseTest.java
index b3e85aeab48..96f20c17742 100644
--- a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PingGenerateParseTest.java
+++ b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PingGenerateParseTest.java
@@ -93,21 +93,26 @@ public class PingGenerateParseTest
         byte[] payload = new byte[8];
         new Random().nextBytes(payload);
 
-        ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
-        generator.generatePing(lease, payload, true);
-
-        for (ByteBuffer buffer : lease.getByteBuffers())
+        // Iterate a few times to be sure generator and parser are properly reset.
+        for (int i = 0; i < 2; ++i)
         {
-            while (buffer.hasRemaining())
-            {
-                parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
-            }
-        }
+            ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
+            generator.generatePing(lease, payload, true);
 
-        Assert.assertEquals(1, frames.size());
-        PingFrame frame = frames.get(0);
-        Assert.assertArrayEquals(payload, frame.getPayload());
-        Assert.assertTrue(frame.isReply());
+            frames.clear();
+            for (ByteBuffer buffer : lease.getByteBuffers())
+            {
+                while (buffer.hasRemaining())
+                {
+                    parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
+                }
+            }
+
+            Assert.assertEquals(1, frames.size());
+            PingFrame frame = frames.get(0);
+            Assert.assertArrayEquals(payload, frame.getPayload());
+            Assert.assertTrue(frame.isReply());
+        }
     }
 
     @Test
diff --git a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PriorityGenerateParseTest.java b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PriorityGenerateParseTest.java
index 44dbc0cebba..664c4dd181b 100644
--- a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PriorityGenerateParseTest.java
+++ b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PriorityGenerateParseTest.java
@@ -98,22 +98,27 @@ public class PriorityGenerateParseTest
         int weight = 3;
         boolean exclusive = true;
 
-        ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
-        generator.generatePriority(lease, streamId, parentStreamId, weight, exclusive);
-
-        for (ByteBuffer buffer : lease.getByteBuffers())
+        // Iterate a few times to be sure generator and parser are properly reset.
+        for (int i = 0; i < 2; ++i)
         {
-            while (buffer.hasRemaining())
-            {
-                parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
-            }
-        }
+            ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
+            generator.generatePriority(lease, streamId, parentStreamId, weight, exclusive);
 
-        Assert.assertEquals(1, frames.size());
-        PriorityFrame frame = frames.get(0);
-        Assert.assertEquals(streamId, frame.getStreamId());
-        Assert.assertEquals(parentStreamId, frame.getParentStreamId());
-        Assert.assertEquals(weight, frame.getWeight());
-        Assert.assertEquals(exclusive, frame.isExclusive());
+            frames.clear();
+            for (ByteBuffer buffer : lease.getByteBuffers())
+            {
+                while (buffer.hasRemaining())
+                {
+                    parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
+                }
+            }
+
+            Assert.assertEquals(1, frames.size());
+            PriorityFrame frame = frames.get(0);
+            Assert.assertEquals(streamId, frame.getStreamId());
+            Assert.assertEquals(parentStreamId, frame.getParentStreamId());
+            Assert.assertEquals(weight, frame.getWeight());
+            Assert.assertEquals(exclusive, frame.isExclusive());
+        }
     }
 }
diff --git a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PushPromiseGenerateParseTest.java b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PushPromiseGenerateParseTest.java
index 78a08f9796d..fd3d50c68f4 100644
--- a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PushPromiseGenerateParseTest.java
+++ b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PushPromiseGenerateParseTest.java
@@ -115,28 +115,33 @@ public class PushPromiseGenerateParseTest
         fields.put("User-Agent", "Jetty");
         MetaData.Request metaData = new MetaData.Request("GET", HttpScheme.HTTP, new HostPortHttpField("localhost:8080"), "/path", HttpVersion.HTTP_2, fields);
 
-        ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
-        generator.generatePushPromise(lease, streamId, promisedStreamId, metaData);
-
-        for (ByteBuffer buffer : lease.getByteBuffers())
+        // Iterate a few times to be sure generator and parser are properly reset.
+        for (int i = 0; i < 2; ++i)
         {
-            while (buffer.hasRemaining())
+            ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
+            generator.generatePushPromise(lease, streamId, promisedStreamId, metaData);
+
+            frames.clear();
+            for (ByteBuffer buffer : lease.getByteBuffers())
             {
-                parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
+                while (buffer.hasRemaining())
+                {
+                    parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
+                }
             }
-        }
 
-        Assert.assertEquals(1, frames.size());
-        PushPromiseFrame frame = frames.get(0);
-        Assert.assertEquals(streamId, frame.getStreamId());
-        Assert.assertEquals(promisedStreamId, frame.getPromisedStreamId());
-        MetaData.Request request = (MetaData.Request)frame.getMetaData();
-        Assert.assertEquals(metaData.getMethod(), request.getMethod());
-        Assert.assertEquals(metaData.getURI(), request.getURI());
-        for (int j = 0; j < fields.size(); ++j)
-        {
-            HttpField field = fields.getField(j);
-            Assert.assertTrue(request.getFields().contains(field));
+            Assert.assertEquals(1, frames.size());
+            PushPromiseFrame frame = frames.get(0);
+            Assert.assertEquals(streamId, frame.getStreamId());
+            Assert.assertEquals(promisedStreamId, frame.getPromisedStreamId());
+            MetaData.Request request = (MetaData.Request)frame.getMetaData();
+            Assert.assertEquals(metaData.getMethod(), request.getMethod());
+            Assert.assertEquals(metaData.getURI(), request.getURI());
+            for (int j = 0; j < fields.size(); ++j)
+            {
+                HttpField field = fields.getField(j);
+                Assert.assertTrue(request.getFields().contains(field));
+            }
         }
     }
 }
diff --git a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/ResetGenerateParseTest.java b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/ResetGenerateParseTest.java
index 66633e64e2f..8936c5372f1 100644
--- a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/ResetGenerateParseTest.java
+++ b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/ResetGenerateParseTest.java
@@ -92,20 +92,25 @@ public class ResetGenerateParseTest
         int streamId = 13;
         int error = 17;
 
-        ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
-        generator.generateReset(lease, streamId, error);
-
-        for (ByteBuffer buffer : lease.getByteBuffers())
+        // Iterate a few times to be sure generator and parser are properly reset.
+        for (int i = 0; i < 2; ++i)
         {
-            while (buffer.hasRemaining())
-            {
-                parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
-            }
-        }
+            ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
+            generator.generateReset(lease, streamId, error);
 
-        Assert.assertEquals(1, frames.size());
-        ResetFrame frame = frames.get(0);
-        Assert.assertEquals(streamId, frame.getStreamId());
-        Assert.assertEquals(error, frame.getError());
+            frames.clear();
+            for (ByteBuffer buffer : lease.getByteBuffers())
+            {
+                while (buffer.hasRemaining())
+                {
+                    parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
+                }
+            }
+
+            Assert.assertEquals(1, frames.size());
+            ResetFrame frame = frames.get(0);
+            Assert.assertEquals(streamId, frame.getStreamId());
+            Assert.assertEquals(error, frame.getError());
+        }
     }
 }
diff --git a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/SettingsGenerateParseTest.java b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/SettingsGenerateParseTest.java
index 15343f406ca..c0a7ee633a7 100644
--- a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/SettingsGenerateParseTest.java
+++ b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/SettingsGenerateParseTest.java
@@ -155,22 +155,27 @@ public class SettingsGenerateParseTest
         Integer value = 17;
         settings1.put(key, value);
 
-        ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
-        generator.generateSettings(lease, settings1, true);
-
-        for (ByteBuffer buffer : lease.getByteBuffers())
+        // Iterate a few times to be sure generator and parser are properly reset.
+        for (int i = 0; i < 2; ++i)
         {
-            while (buffer.hasRemaining())
-            {
-                parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
-            }
-        }
+            ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
+            generator.generateSettings(lease, settings1, true);
 
-        Assert.assertEquals(1, frames.size());
-        SettingsFrame frame = frames.get(0);
-        Map<Integer, Integer> settings2 = frame.getSettings();
-        Assert.assertEquals(1, settings2.size());
-        Assert.assertEquals(value, settings2.get(key));
-        Assert.assertTrue(frame.isReply());
+            frames.clear();
+            for (ByteBuffer buffer : lease.getByteBuffers())
+            {
+                while (buffer.hasRemaining())
+                {
+                    parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
+                }
+            }
+
+            Assert.assertEquals(1, frames.size());
+            SettingsFrame frame = frames.get(0);
+            Map<Integer, Integer> settings2 = frame.getSettings();
+            Assert.assertEquals(1, settings2.size());
+            Assert.assertEquals(value, settings2.get(key));
+            Assert.assertTrue(frame.isReply());
+        }
     }
 }
diff --git a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/WindowUpdateGenerateParseTest.java b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/WindowUpdateGenerateParseTest.java
index 3cd2e6bdcc8..1a53d241e0f 100644
--- a/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/WindowUpdateGenerateParseTest.java
+++ b/jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/WindowUpdateGenerateParseTest.java
@@ -92,20 +92,25 @@ public class WindowUpdateGenerateParseTest
         int streamId = 13;
         int windowUpdate = 17;
 
-        ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
-        generator.generateWindowUpdate(lease, streamId, windowUpdate);
-
-        for (ByteBuffer buffer : lease.getByteBuffers())
+        // Iterate a few times to be sure generator and parser are properly reset.
+        for (int i = 0; i < 2; ++i)
         {
-            while (buffer.hasRemaining())
-            {
-                parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
-            }
-        }
+            ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
+            generator.generateWindowUpdate(lease, streamId, windowUpdate);
 
-        Assert.assertEquals(1, frames.size());
-        WindowUpdateFrame frame = frames.get(0);
-        Assert.assertEquals(streamId, frame.getStreamId());
-        Assert.assertEquals(windowUpdate, frame.getWindowDelta());
+            frames.clear();
+            for (ByteBuffer buffer : lease.getByteBuffers())
+            {
+                while (buffer.hasRemaining())
+                {
+                    parser.parse(ByteBuffer.wrap(new byte[]{buffer.get()}));
+                }
+            }
+
+            Assert.assertEquals(1, frames.size());
+            WindowUpdateFrame frame = frames.get(0);
+            Assert.assertEquals(streamId, frame.getStreamId());
+            Assert.assertEquals(windowUpdate, frame.getWindowDelta());
+        }
     }
 }