diff --git a/radio/src/common/arm/CMakeLists.txt b/radio/src/common/arm/CMakeLists.txt
index fade603c2..46c405182 100644
--- a/radio/src/common/arm/CMakeLists.txt
+++ b/radio/src/common/arm/CMakeLists.txt
@@ -70,7 +70,7 @@ if(HAPTIC)
 endif()
 if(MULTIMODULE)
   add_definitions(-DMULTIMODULE)
-  set(SRC ${SRC} pulses/multi_arm.cpp)
+  set(SRC ${SRC} pulses/multi_arm.cpp telemetry/spektrum.cpp)
 endif()
 add_definitions(-DCPUARM)
 add_definitions(-DFRSKY -DFRSKY_SPORT -DFRSKY_HUB -DGPS -DPXX -DDSM2)