diff --git a/makefiles/app_dirs.inc.mk b/makefiles/app_dirs.inc.mk
index ec5611a088..6659b2df1b 100644
--- a/makefiles/app_dirs.inc.mk
+++ b/makefiles/app_dirs.inc.mk
@@ -17,6 +17,7 @@ APPLICATION_DIRS :=                   \
     tests/bench                       \
     tests/build_system                \
     tests/core                        \
+    tests/cpu                         \
     tests/drivers                     \
     tests/periph                      \
     tests/pkg                         \