--- a/src/hotspot/share/jfr/metadata/GenerateJfrFiles.java	Wed May 16 12:38:35 2018 +0200
+++ b/src/hotspot/share/jfr/metadata/GenerateJfrFiles.java	Wed May 16 13:14:58 2018 +0200
@@ -450,6 +450,7 @@
             out.write("#ifndef JFRFILES_JFREVENTCLASSES_HPP");
             out.write("#define JFRFILES_JFREVENTCLASSES_HPP");
             out.write("");
+            out.write("#include \"oops/klass.hpp\"");
             out.write("#include \"jfrfiles/jfrTypes.hpp\"");
             out.write("#include \"jfr/utilities/jfrTypes.hpp\"");
             out.write("#include \"utilities/macros.hpp\"");
@@ -689,4 +690,4 @@
     private static void printField(Printer out, FieldElement field) {
         out.write("  " + field.getFieldType() + " _" + field.name + ";");
     }
-}
\ No newline at end of file
+}