diff --git a/utils/lit/lit/TestingConfig.py b/utils/lit/lit/TestingConfig.py
index 1e39a000c90d..f3c0b11faafb 100644
--- a/utils/lit/lit/TestingConfig.py
+++ b/utils/lit/lit/TestingConfig.py
@@ -25,7 +25,8 @@ def fromdefaults(litConfig):
         pass_vars = ['LIBRARY_PATH', 'LD_LIBRARY_PATH', 'SYSTEMROOT', 'TERM',
                      'LD_PRELOAD', 'ASAN_OPTIONS', 'UBSAN_OPTIONS',
                      'LSAN_OPTIONS', 'ADB', 'ANDROID_SERIAL',
-                     'SANITIZER_IGNORE_CVE_2016_2143']
+                     'SANITIZER_IGNORE_CVE_2016_2143', 'TMPDIR', 'TMP', 'TEMP',
+                     'TEMPDIR']
         for var in pass_vars:
             val = os.environ.get(var, '')
             # Check for empty string as some variables such as LD_PRELOAD cannot be empty
@@ -42,16 +43,6 @@ def fromdefaults(litConfig):
                     'TMP' : os.environ.get('TMP',''),
                     })
 
-        # The option to preserve TEMP, TMP, and TMPDIR.
-        # This is intended to check how many temporary files would be generated
-        # (and be not cleaned up) in automated builders.
-        if 'LIT_PRESERVES_TMP' in os.environ:
-            environment.update({
-                    'TEMP' : os.environ.get('TEMP',''),
-                    'TMP' : os.environ.get('TMP',''),
-                    'TMPDIR' : os.environ.get('TMPDIR',''),
-                    })
-
         # Set the default available features based on the LitConfig.
         available_features = []
         if litConfig.useValgrind:
diff --git a/utils/lit/lit/main.py b/utils/lit/lit/main.py
index 30ae8b3e5332..243a9dddb462 100755
--- a/utils/lit/lit/main.py
+++ b/utils/lit/lit/main.py
@@ -8,6 +8,8 @@
 
 from __future__ import absolute_import
 import math, os, platform, random, re, sys, time
+import tempfile
+import shutil
 
 import lit.ProgressBar
 import lit.LitConfig
@@ -132,6 +134,30 @@ def sortIndex(test):
     run.tests.sort(key = lambda t: sortIndex(t))
 
 def main(builtinParameters = {}):
+    # Create a temp directory inside the normal temp directory so that we can
+    # try to avoid temporary test file leaks. The user can avoid this behavior
+    # by setting LIT_PRESERVES_TMP in the environment, so they can easily use
+    # their own temp directory to monitor temporary file leaks or handle them at
+    # the buildbot level.
+    lit_tmp = None
+    if 'LIT_PRESERVES_TMP' not in os.environ:
+        lit_tmp = tempfile.mkdtemp(prefix="lit_tmp_")
+        os.environ.update({
+                'TMPDIR': lit_tmp,
+                'TMP': lit_tmp,
+                'TEMP': lit_tmp,
+                'TEMPDIR': lit_tmp,
+                })
+    # FIXME: If Python does not exit cleanly, this directory will not be cleaned
+    # up. We should consider writing the lit pid into the temp directory,
+    # scanning for stale temp directories, and deleting temp directories whose
+    # lit process has died.
+    try:
+        main_with_tmp(builtinParameters)
+    finally:
+        shutil.rmtree(lit_tmp)
+
+def main_with_tmp(builtinParameters):
     global options
     from optparse import OptionParser, OptionGroup
     parser = OptionParser("usage: %prog [options] {file-or-path}")