diff --git a/.gitignore b/.gitignore
index b64ad391105..386862fcf1a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -40,6 +40,7 @@ fixed_length_file_out
 third_party/gyp/
 third_party/v8/
 third_party/closure_compiler_src/
+third_party/WebCore/
 tests/co19/src/
 
 # Built by chromebot and downloaded from Google Storage