diff --git a/gtsam/slam/StereoFactor.h b/gtsam/slam/StereoFactor.h
index 79c2d93a4..b12dbdf27 100644
--- a/gtsam/slam/StereoFactor.h
+++ b/gtsam/slam/StereoFactor.h
@@ -20,6 +20,7 @@
 
 #include <gtsam/slam/visualSLAM.h>
 #include <gtsam/geometry/Cal3_S2.h>
+#include <gtsam/geometry/StereoCamera.h>
 
 namespace gtsam {