diff --git a/libraries/AP_Math/examples/eulers/make.inc b/libraries/AP_Math/examples/eulers/make.inc
index b20141d400..f9e7eced33 100644
--- a/libraries/AP_Math/examples/eulers/make.inc
+++ b/libraries/AP_Math/examples/eulers/make.inc
@@ -30,3 +30,4 @@ LIBRARIES += Filter
 LIBRARIES += GCS_MAVLink
 LIBRARIES += SITL
 LIBRARIES += StorageManager
+LIBRARIES += AP_OpticalFlow