diff --git a/gtsam/gtsam.i b/gtsam/gtsam.i
index 6c61f3008..f52b6cedd 100644
--- a/gtsam/gtsam.i
+++ b/gtsam/gtsam.i
@@ -2961,6 +2961,13 @@ class BinaryMeasurement {
 typedef gtsam::BinaryMeasurement<gtsam::Unit3> BinaryMeasurementUnit3;
 typedef gtsam::BinaryMeasurement<gtsam::Rot3> BinaryMeasurementRot3;
 
+class BinaryMeasurementsUnit3 {
+  BinaryMeasurementsUnit3();
+  size_t size() const;
+  gtsam::BinaryMeasurement<gtsam::Unit3> at(size_t idx) const;
+  void push_back(const gtsam::BinaryMeasurement<gtsam::Unit3>& measurement);
+};
+
 #include <gtsam/sfm/ShonanAveraging.h>
 
 // TODO(frank): copy/pasta below until we have integer template paremeters in wrap!