diff --git a/ext/objspace/objspace_dump.c b/ext/objspace/objspace_dump.c
index 4e46988..798d0da 100644
--- a/ext/objspace/objspace_dump.c
+++ b/ext/objspace/objspace_dump.c
@@ -92,6 +92,18 @@ dump_append_string_value(struct dump_config *dc, VALUE obj)
 static inline const char *
 obj_type(VALUE obj)
 {
+    if (IMMEDIATE_P(obj)) {
+	if (FIXNUM_P(obj)) return "FIXNUM";
+        if (FLONUM_P(obj)) return "FLOAT";
+        if (obj == Qtrue)  return "TRUE";
+	if (STATIC_SYM_P(obj)) return "SYMBOL";
+	if (obj == Qundef) return "UNDEF";
+    }
+    else if (!RTEST(obj)) {
+	if (obj == Qnil)   return "NIL";
+	if (obj == Qfalse) return "FALSE";
+    }
+
     switch (BUILTIN_TYPE(obj)) {
 #define CASE_TYPE(type) case T_##type: return #type; break
 	CASE_TYPE(NONE);
@@ -150,7 +162,7 @@ dump_object(VALUE obj, struct dump_config *dc)
     size_t n, i;
 
     if (SPECIAL_CONST_P(obj)) {
-      dump_append(dc, "{}");
+      dump_append(dc, "{\"type\":\"%s\"}",  obj_type(obj));
       return;
     }
 
diff --git a/test/objspace/test_objspace.rb b/test/objspace/test_objspace.rb
index 01f31cc..d5c8cb4 100644
--- a/test/objspace/test_objspace.rb
+++ b/test/objspace/test_objspace.rb
@@ -245,11 +245,11 @@ class TestObjSpace < Test::Unit::TestCase
 
   def test_dump_special_consts
     # [ruby-core:69692] [Bug #11291]
-    assert_equal('{}', ObjectSpace.dump(nil))
-    assert_equal('{}', ObjectSpace.dump(true))
-    assert_equal('{}', ObjectSpace.dump(false))
-    assert_equal('{}', ObjectSpace.dump(0))
-    assert_equal('{}', ObjectSpace.dump(:foo))
+    assert_equal('{"type":"NIL"}', ObjectSpace.dump(nil))
+    assert_equal('{"type":"TRUE"}', ObjectSpace.dump(true))
+    assert_equal('{"type":"FALSE"}', ObjectSpace.dump(false))
+    assert_equal('{"type":"FIXNUM"}', ObjectSpace.dump(0))
+    assert_equal('{"type":"SYMBOL"}', ObjectSpace.dump(:foo))
   end
 
   def test_dump_all