diff --git a/src/unix-adapter/Event.h b/src/unix-adapter/Event.h
index 5a6ff98..958eb2e 100755
--- a/src/unix-adapter/Event.h
+++ b/src/unix-adapter/Event.h
@@ -49,6 +49,7 @@ public:
 private:
     // Do not allow copying the Event object.
     Event(const Event &other);
+    Event &operator=(const Event &other);
 
 private:
     HANDLE m_handle;
diff --git a/src/unix-adapter/WakeupFd.h b/src/unix-adapter/WakeupFd.h
index d6d4d0c..dd8d362 100644
--- a/src/unix-adapter/WakeupFd.h
+++ b/src/unix-adapter/WakeupFd.h
@@ -32,6 +32,7 @@ public:
 private:
     // Do not allow copying the WakeupFd object.
     WakeupFd(const WakeupFd &other);
+    WakeupFd &operator=(const WakeupFd &other);
 
 private:
     int m_pipeReadFd;