--- old/src/hotspot/share/runtime/vframe_hp.hpp	2020-07-21 14:10:35.762723624 +0200
+++ new/src/hotspot/share/runtime/vframe_hp.hpp	2020-07-21 14:10:35.642721830 +0200
@@ -27,6 +27,8 @@
 
 #include "runtime/vframe.hpp"
 
+class MonitorInfo;
+
 class compiledVFrame: public javaVFrame {
  public:
   // JVM state