Bug #7825

gistfile1.diff

diff --git a/vm.c b/vm.c
index 36def2c..89314c7 100644
--- a/vm.c
+++ b/vm.c
@@ -1782,7 +1782,14 @@ rb_thread_mark(void *ptr)
    	if (iseq) {
 		    rb_gc_mark(RUBY_VM_NORMAL_ISEQ_P(iseq) ? iseq->self : (VALUE)iseq);
 		}
-		if (cfp->me) ((rb_method_entry_t *)cfp->me)->mark = 1;
+		if (cfp->me) {
+		    rb_method_entry_t *me = (rb_method_entry_t *)cfp->me;
+		    rb_method_definition_t *def = me->def;
+		    me->mark = 1;
+		    if (def->type == VM_METHOD_TYPE_BMETHOD) {
+			rb_gc_mark(def->body.proc);
+		    }
+		}
 		cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);
 	    }
 	}