diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6d0cfea..f7b4fd5 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -67,6 +67,7 @@
 
 if (CPU_INFO)
     add_executable (cpuinfoapp src/cpuinfo_main.cpp src/speed_select.cpp
+        src/sst_mailbox.cpp
         src/cpuinfo_utils.cpp)
     target_link_libraries (cpuinfoapp ${SYSTEMD_LIBRARIES})
     target_link_libraries (cpuinfoapp ${DBUSINTERFACE_LIBRARIES})