1 files changed, 1 insertions, 0 deletions
diff --git a/ruby.c b/ruby.c
index afe1e71ae8..f2d368d8b5 100644
--- a/ruby.c
+++ b/ruby.c
@@ -1063,6 +1063,7 @@ ruby_prog_init()
     rb_define_readonly_variable("$-l", &do_line);
 
     rb_define_hooked_variable("$0", &rb_progname, 0, set_arg0);
+    rb_define_hooked_variable("$PROGRAM_NAME", &rb_progname, 0, set_arg0);
 
     rb_argv = rb_ary_new();
     rb_define_readonly_variable("$*", &rb_argv);