diff --git a/include/grgsm/CMakeLists.txt b/include/grgsm/CMakeLists.txt
index dc9b191..beca954 100644
--- a/include/grgsm/CMakeLists.txt
+++ b/include/grgsm/CMakeLists.txt
@@ -33,3 +33,4 @@
 add_subdirectory(misc_utils)
 add_subdirectory(qa_utils)
 add_subdirectory(flow_control)
+add_subdirectory(trx_interface)