diff --git a/sys/cpp11-compat/include/riot/condition_variable.hpp b/sys/cpp11-compat/include/riot/condition_variable.hpp
index 1897f752a7..3f0a3014ae 100644
--- a/sys/cpp11-compat/include/riot/condition_variable.hpp
+++ b/sys/cpp11-compat/include/riot/condition_variable.hpp
@@ -26,6 +26,7 @@
 
 #include "sched.h"
 #include "xtimer.h"
+#include "priority_queue.h"
 
 #include "riot/mutex.hpp"
 #include "riot/chrono.hpp"