ext/stackprof.c in stackprof-0.2.8 vs ext/stackprof.c in stackprof-0.2.9

@@ -527,10 +527,10 @@
     S(out);
     S(frames);
     S(aggregate);
 #undef S
 
-    gc_hook = Data_Wrap_Struct(rb_cObject, stackprof_gc_mark, NULL, NULL);
+    gc_hook = Data_Wrap_Struct(rb_cObject, stackprof_gc_mark, NULL, &_stackprof);
     rb_global_variable(&gc_hook);
 
     rb_mStackProf = rb_define_module("StackProf");
     rb_define_singleton_method(rb_mStackProf, "running?", stackprof_running_p, 0);
     rb_define_singleton_method(rb_mStackProf, "run", stackprof_run, -1);