Index: ext/libicpf/src/cfg.h
===================================================================
diff -u -N -r5be423928caafba015f46861cebb10cf0a1bb9ce -r8e565f9442ee4105af5eb0b2bfbc9cec8d3584e4
--- ext/libicpf/src/cfg.h	(.../cfg.h)	(revision 5be423928caafba015f46861cebb10cf0a1bb9ce)
+++ ext/libicpf/src/cfg.h	(.../cfg.h)	(revision 8e565f9442ee4105af5eb0b2bfbc9cec8d3584e4)
@@ -66,7 +66,7 @@
 
 extern config *__g_cfg;
 
-ICPFTEMPL_EXTERN template class LIBICPF_API callback2<ptr_t, ulong_t, ptr_t>;
+ICPFTEMPL_EXTERN template class LIBICPF_API callback2<void, ulong_t, ptr_t>;
 
 /** \brief Structure contain information about one property.
  *