diff --git a/src/app/crash/backup_observer.h b/src/app/crash/backup_observer.h
index 10bdbc7fe..f07d96032 100644
--- a/src/app/crash/backup_observer.h
+++ b/src/app/crash/backup_observer.h
@@ -13,6 +13,7 @@
 #include "app/doc_observer.h"
 #include "app/docs_observer.h"
 
+#include <condition_variable>
 #include <mutex>
 #include <thread>
 #include <vector>