diff --git a/Lib/test/test_tools.py b/Lib/test/test_tools.py
index cbe6d80..564b747 100644
--- a/Lib/test/test_tools.py
+++ b/Lib/test/test_tools.py
@@ -127,6 +127,7 @@
 # Run the tests in Tools/parser/test_unparse.py
 with support.DirsOnSysPath(os.path.join(basepath, 'parser')):
     from test_unparse import UnparseTestCase
+    from test_unparse import DirectoryTestCase
 
 
 def test_main():
diff --git a/Tools/parser/test_unparse.py b/Tools/parser/test_unparse.py
index 647366c..be84400 100644
--- a/Tools/parser/test_unparse.py
+++ b/Tools/parser/test_unparse.py
@@ -2,9 +2,10 @@
 import test.support
 import io
 import os
+import random
 import tokenize
-import ast
 import unparse
+import ast
 
 def read_pyfile(filename):
     """Read and return the contents of a Python source file (as a
@@ -257,6 +258,10 @@
                 if n.endswith('.py') and not n.startswith('bad'):
                     names.append(os.path.join(test_dir, n))
 
+        # Test limited subset of files unless the 'cpu' resource is specified.
+        if not test.support.is_resource_enabled("cpu"):
+            names = random.sample(names, 10)
+
         for filename in names:
             if test.support.verbose:
                 print('Testing %s' % filename)