diff --git a/jetty-http/src/main/java/org/eclipse/jetty/http/HttpParser.java b/jetty-http/src/main/java/org/eclipse/jetty/http/HttpParser.java
index 51d8b19770cb..41c7117a460d 100644
--- a/jetty-http/src/main/java/org/eclipse/jetty/http/HttpParser.java
+++ b/jetty-http/src/main/java/org/eclipse/jetty/http/HttpParser.java
@@ -1935,6 +1935,7 @@ protected void setState(FieldState state)
 
     public Index<HttpField> getFieldCache()
     {
+        checkHeaderCache();
         return _fieldCache;
     }