diff --git a/test/ruby/test_process.rb b/test/ruby/test_process.rb
index eb114dbebb..ba7b0f1177 100644
--- a/test/ruby/test_process.rb
+++ b/test/ruby/test_process.rb
@@ -1373,6 +1373,14 @@ class TestProcess < Test::Unit::TestCase
     }
   end
 
+  def test_argv0_keep_alive
+    assert_in_out_err([], <<~REPRO, ['-'], [], "[Bug #15887]")
+      $0 = "diverge"
+      4.times { GC.start }
+      puts Process.argv0
+    REPRO
+  end
+
   def test_status
     with_tmpchdir do
       s = run_in_child("exit 1")
diff --git a/version.h b/version.h
index d80632ce74..f9096b5537 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.5.6"
 #define RUBY_RELEASE_DATE "2019-08-27"
-#define RUBY_PATCHLEVEL 179
+#define RUBY_PATCHLEVEL 180
 
 #define RUBY_RELEASE_YEAR 2019
 #define RUBY_RELEASE_MONTH 8
diff --git a/vm.c b/vm.c
index 5d15734055..bf7bbbf43c 100644
--- a/vm.c
+++ b/vm.c
@@ -2100,6 +2100,7 @@ rb_vm_mark(void *ptr)
 	rb_gc_mark(vm->loaded_features);
 	rb_gc_mark(vm->loaded_features_snapshot);
 	rb_gc_mark(vm->top_self);
+        rb_gc_mark(vm->orig_progname);
 	RUBY_MARK_UNLESS_NULL(vm->coverages);
 	rb_gc_mark(vm->defined_module_hash);