diff --git a/rx/CMakeLists.txt b/rx/CMakeLists.txt
index aef9b800e..aeb489352 100644
--- a/rx/CMakeLists.txt
+++ b/rx/CMakeLists.txt
@@ -7,6 +7,7 @@ add_library(${PROJECT_NAME} OBJECT
     src/die.cpp
     src/FileLock.cpp
     src/hexdump.cpp
+    src/Mappable.cpp
     src/mem.cpp
     src/Process.cpp
     src/SharedAtomic.cpp