diff --git a/tile/base/thread/cond_var.h b/tile/base/thread/cond_var.h
index 9118a03..41e1d73 100644
--- a/tile/base/thread/cond_var.h
+++ b/tile/base/thread/cond_var.h
@@ -113,6 +113,7 @@ private:
     }
 
 private:
+    friend class ScopedLock;
     CondVarProxy proxy_;
 };
 }// namespace cond_var
diff --git a/tile/base/thread/event.h b/tile/base/thread/event.h
index 61f9c2b..8386191 100644
--- a/tile/base/thread/event.h
+++ b/tile/base/thread/event.h
@@ -3,7 +3,6 @@
 
 #pragma once
 
-#include "tile/base/thread/cond_var.h"
 #include "tile/base/thread/mutex.h"
 #include "tile/base/thread/scoped_lock.h"
 
@@ -30,7 +29,7 @@ public:
     inline void Wait()
     {
         ScopedLock _(m_);
-        cv_.Wait(m_, [this] { return signaled_; });
+        cv_.Wait(_, [this] { return signaled_; });
         ResetIfNeeded();
     }
 
@@ -49,7 +48,7 @@ public:
     bool WaitUntil(const std::chrono::time_point<Clock, Duration> &timeout_time)
     {
         ScopedLock _(m_);
-        if (cv_.WaitUntil(m_, timeout_time, [this] { return signaled_; })) {
+        if (cv_.WaitUntil(_, timeout_time, [this] { return signaled_; })) {
             ResetIfNeeded();
             return true;
         }
diff --git a/tile/tile.h b/tile/tile.h
index de94d47..e05523a 100644
--- a/tile/tile.h
+++ b/tile/tile.h
@@ -39,7 +39,6 @@
 #include "tile/base/write_mostly.h"
 
 // Sync
-#include "tile/base/thread/cond_var.h"
 #include "tile/base/thread/event.h"
 #include "tile/base/thread/latch.h"
 #include "tile/base/thread/mutex.h"