diff --git a/src/thread_list.h b/src/thread_list.h
index 9e45bfb..dc6e820 100644
--- a/src/thread_list.h
+++ b/src/thread_list.h
@@ -22,6 +22,8 @@
 
 namespace art {
 
+class TimingLogger;
+
 class ThreadList {
  public:
   static const uint32_t kMaxThreadId = 0xFFFF;