diff --git a/EKF/CMakeLists.txt b/EKF/CMakeLists.txt
index e4010f3e1c..0d7d6a93e9 100644
--- a/EKF/CMakeLists.txt
+++ b/EKF/CMakeLists.txt
@@ -66,6 +66,7 @@ set(SRCS
 	mag_fusion.cpp
 	gps_checks.cpp
 	airspeed_fusion.cpp
+	sideslip_fusion.cpp
 	control.cpp
 	geo.cpp
 	mathlib.cpp