diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 65feb228f..8cb92b2ae 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -26,4 +26,6 @@
 #  POSSIBILITY OF SUCH DAMAGE.
 #
 
+if(OT_FTD)
 add_subdirectory(unit)
+endif()