diff --git allocator.gyp allocator.gyp
index c20325d..0e34390 100644
--- allocator.gyp
+++ allocator.gyp
@@ -238,6 +238,7 @@
             '<(tcmalloc_dir)/src/base/atomicops-internals-linuxppc.h',
             '<(tcmalloc_dir)/src/base/atomicops-internals-macosx.h',
             '<(tcmalloc_dir)/src/base/atomicops-internals-x86-msvc.h',
+            '<(tcmalloc_dir)/src/base/atomicops-internals-x86.cc',
             '<(tcmalloc_dir)/src/base/atomicops-internals-x86.h',
             '<(tcmalloc_dir)/src/base/atomicops.h',
             '<(tcmalloc_dir)/src/base/basictypes.h',