diff --git a/CMakeLists.txt b/CMakeLists.txt
index b16bfcf646..12d688ee7d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -53,6 +53,7 @@ px4_add_module(
 		EKF/mag_fusion.cpp
 		EKF/gps_checks.cpp
 		EKF/airspeed_fusion.cpp
+		EKF/sideslip_fusion.cpp
 		EKF/optflow_fusion.cpp
 		EKF/control.cpp
 		EKF/terrain_estimator.cpp