diff --git a/src/system_wrappers/source/system_wrappers.gyp b/src/system_wrappers/source/system_wrappers.gyp
index 1b491ab42e..c4785ff75a 100644
--- a/src/system_wrappers/source/system_wrappers.gyp
+++ b/src/system_wrappers/source/system_wrappers.gyp
@@ -149,6 +149,8 @@
           'sources!': [
             'cpu.cc',
             'trace_impl.cc',
+            'trace_posix.cc',
+            'trace_windows.cc',
           ],
         }, {
           'sources!': [