diff --git a/jetty-core/jetty-http2/jetty-http2-common/src/main/java/org/eclipse/jetty/http2/parser/Parser.java b/jetty-core/jetty-http2/jetty-http2-common/src/main/java/org/eclipse/jetty/http2/parser/Parser.java
index fbb7bdb2b5f6..2973005ea8af 100644
--- a/jetty-core/jetty-http2/jetty-http2-common/src/main/java/org/eclipse/jetty/http2/parser/Parser.java
+++ b/jetty-core/jetty-http2/jetty-http2-common/src/main/java/org/eclipse/jetty/http2/parser/Parser.java
@@ -54,8 +54,8 @@ public class Parser
     private int maxSettingsKeys = SettingsFrame.DEFAULT_MAX_KEYS;
     private boolean continuation;
     private State state = State.HEADER;
-    private long beginNanoTime = Long.MIN_VALUE;
-    private boolean nanoTimeRead = true;
+    private long beginNanoTime;
+    private boolean nanoTimeStored;
 
     public Parser(ByteBufferPool bufferPool, int maxHeaderSize)
     {
@@ -66,11 +66,7 @@ public Parser(ByteBufferPool bufferPool, int maxHeaderSize, RateControl rateCont
     {
         this.bufferPool = bufferPool;
         this.headerParser = new HeaderParser(rateControl == null ? RateControl.NO_RATE_CONTROL : rateControl);
-        this.hpackDecoder = new HpackDecoder(maxHeaderSize, () ->
-        {
-            nanoTimeRead = true;
-            return beginNanoTime;
-        });
+        this.hpackDecoder = new HpackDecoder(maxHeaderSize, this::loadAndClearBeginNanoTime);
         this.bodyParsers = new BodyParser[FrameType.values().length];
     }
 
@@ -108,18 +104,22 @@ private void reset()
     {
         headerParser.reset();
         state = State.HEADER;
-        beginNanoTime = Long.MIN_VALUE;
-        nanoTimeRead = true;
+        nanoTimeStored = false;
+    }
+
+    private long loadAndClearBeginNanoTime()
+    {
+        long beginNanoTime = this.beginNanoTime;
+        nanoTimeStored = false;
+        return beginNanoTime;
     }
 
-    protected void takeNanoTime()
+    private void storeBeginNanoTime()
     {
-        if (nanoTimeRead)
+        if (!nanoTimeStored)
         {
-            beginNanoTime = NanoTime.now(); // TODO #9900 check beginNanoTime's accuracy
-            if (beginNanoTime == Long.MIN_VALUE)
-                beginNanoTime++;
-            nanoTimeRead = false;
+            beginNanoTime = NanoTime.now();
+            nanoTimeStored = true;
         }
     }
 
@@ -138,9 +138,9 @@ public void parse(ByteBuffer buffer)
     {
         try
         {
-            takeNanoTime();
             while (true)
             {
+                storeBeginNanoTime();
                 switch (state)
                 {
                     case HEADER:
diff --git a/jetty-core/jetty-http2/jetty-http2-common/src/main/java/org/eclipse/jetty/http2/parser/ServerParser.java b/jetty-core/jetty-http2/jetty-http2-common/src/main/java/org/eclipse/jetty/http2/parser/ServerParser.java
index 978c46354de3..4aa82b654c32 100644
--- a/jetty-core/jetty-http2/jetty-http2-common/src/main/java/org/eclipse/jetty/http2/parser/ServerParser.java
+++ b/jetty-core/jetty-http2/jetty-http2-common/src/main/java/org/eclipse/jetty/http2/parser/ServerParser.java
@@ -86,7 +86,6 @@ public void parse(ByteBuffer buffer)
         {
             if (LOG.isDebugEnabled())
                 LOG.debug("Parsing {}", buffer);
-            takeNanoTime();
             while (true)
             {
                 switch (state)