diff --git a/base/message_loop/message_pump_libevent.cc b/base/message_loop/message_pump_libevent.cc
index fef01da..ac1fb07 100644
--- a/base/message_loop/message_pump_libevent.cc
+++ b/base/message_loop/message_pump_libevent.cc
@@ -14,7 +14,11 @@
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
+#if defined(USE_SYSTEM_LIBEVENT)
+#include <event.h>
+#else
 #include "base/third_party/libevent/event.h"
+#endif
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
diff --git a/tools/gn/bootstrap/bootstrap.py b/tools/gn/bootstrap/bootstrap.py
index b07fd0a..de1383d 100755
--- a/tools/gn/bootstrap/bootstrap.py
+++ b/tools/gn/bootstrap/bootstrap.py
@@ -17,6 +17,7 @@ it with its own BUILD.gn to the final destination.
 
 import contextlib
 import errno
+import filecmp
 import logging
 import optparse
 import os
@@ -594,6 +595,12 @@ def write_gn_ninja(path, root_gen_dir, options):
         'base/third_party/libevent/epoll.c',
     ])
 
+    f1 = os.path.join(SRC_ROOT, 'build/linux/unbundle/libevent.gn')
+    f2 = os.path.join(SRC_ROOT, 'base/third_party/libevent/BUILD.gn')
+    if os.path.isfile(f1) and os.path.isfile(f2) and filecmp.cmp(f1, f2):
+      del static_libraries['libevent']
+      cflags.extend(['-DUSE_SYSTEM_LIBEVENT'])
+      libs.extend(['-levent'])
 
   if is_mac:
     static_libraries['base']['sources'].extend([
diff --git a/tools/generate_shim_headers/generate_shim_headers.py b/tools/generate_shim_headers/generate_shim_headers.py
index 1b8e27f..0b25f09 100755
--- a/tools/generate_shim_headers/generate_shim_headers.py
+++ b/tools/generate_shim_headers/generate_shim_headers.py
@@ -67,6 +67,12 @@ def GeneratorMain(argv):
       if options.generate:
         header_path = os.path.join(target_directory, header_filename)
         header_dir = os.path.dirname(header_path)
+        source_header = os.path.join(root, header_filename)
+        if os.path.isfile(source_header):
+          try:
+            os.rename(source_header, source_header + '.orig')
+          except:
+            pass
         if not os.path.exists(header_dir):
           os.makedirs(header_dir)
         with open(header_path, 'w') as f: