diff --git a/lib/pp.rb b/lib/pp.rb
index 5e5fd06cae..fb7aa7b41c 100644
--- a/lib/pp.rb
+++ b/lib/pp.rb
@@ -422,7 +422,9 @@ end
 
 class Data # :nodoc:
   def pretty_print(q) # :nodoc:
-    q.group(1, sprintf("#<data %s", PP.mcall(self, Kernel, :class).name), '>') {
+    class_name = PP.mcall(self, Kernel, :class).name
+    class_name = " #{class_name}" if class_name
+    q.group(1, "#<data#{class_name}", '>') {
       q.seplist(PP.mcall(self, Kernel, :class).members, lambda { q.text "," }) {|member|
         q.breakable
         q.text member.to_s
diff --git a/test/test_pp.rb b/test/test_pp.rb
index d7cca82a00..72a4f127f3 100644
--- a/test/test_pp.rb
+++ b/test/test_pp.rb
@@ -149,6 +149,9 @@ class PPCycleTest < Test::Unit::TestCase
       a = D.new("aaa", "bbb")
       assert_equal("#<data PPTestModule::PPCycleTest::D\n aaa=\"aaa\",\n bbb=\"bbb\">\n", PP.pp(a, ''.dup, 20))
       assert_equal("#{a.inspect}\n", PP.pp(a, ''.dup))
+
+      b = Data.define(:a).new(42)
+      assert_equal("#{b.inspect}\n", PP.pp(b, ''.dup))
     end
   end