diff --git a/libraries/AP_Math/vector3.cpp b/libraries/AP_Math/vector3.cpp
index 669ecb2f287..9a1ff1a93bd 100644
--- a/libraries/AP_Math/vector3.cpp
+++ b/libraries/AP_Math/vector3.cpp
@@ -632,5 +632,6 @@ bool Vector3<T>::segment_plane_intersect(const Vector3<T>& seg_start, const Vect
 template class Vector3<float>;
 template class Vector3<double>;
 
-// define needed ops for Vector3l
+// define needed ops for Vector3l, Vector3i as needed
 template Vector3<int32_t> &Vector3<int32_t>::operator +=(const Vector3<int32_t> &v);
+template bool Vector3<int16_t>::operator ==(const Vector3<int16_t> &v) const;