diff --git a/tests/unittests/tests-core/tests-core-mbox.c b/tests/unittests/tests-core/tests-core-mbox.c
index 87e041c7ee..e03c3244b1 100644
--- a/tests/unittests/tests-core/tests-core-mbox.c
+++ b/tests/unittests/tests-core/tests-core-mbox.c
@@ -8,6 +8,8 @@
 
 #include <limits.h>
 
+#include "container.h"
+
 #include "embUnit.h"
 
 #include "mbox.h"