diff --git a/chrome/test/chromedriver/run_all_tests.py b/chrome/test/chromedriver/run_all_tests.py
index 5cbf7e489e2f26..c8f47bd7a9961f 100755
--- a/chrome/test/chromedriver/run_all_tests.py
+++ b/chrome/test/chromedriver/run_all_tests.py
@@ -7,6 +7,7 @@
 
 import optparse
 import os
+import platform
 import sys
 
 import archive
@@ -128,11 +129,14 @@ def main():
   print 'Using build outputs from', build_dir
 
   chromedriver = os.path.join(build_dir, server_name)
+  platform = util.GetPlatformName()
+  if util.IsLinux() and platform.architecture()[0] == '64bit':
+    platform += '64'
   ref_chromedriver = os.path.join(
       chrome_paths.GetSrc(),
       'chrome', 'test', 'chromedriver', 'third_party', 'java_tests',
       'reference_builds',
-      'chromedriver_%s%s' % (util.GetPlatformName(), exe_postfix))
+      'chromedriver_%s%s' % (platform, exe_postfix))
 
   if util.IsLinux():
     # Set LD_LIBRARY_PATH to enable successful loading of shared object files,