diff --git a/gtsam/geometry/EssentialMatrix.h b/gtsam/geometry/EssentialMatrix.h
index d616ac0fa..77d8e98cf 100644
--- a/gtsam/geometry/EssentialMatrix.h
+++ b/gtsam/geometry/EssentialMatrix.h
@@ -145,6 +145,17 @@ public:
     return q;
   }
 
+  /**
+   * Given essential matrix E in camera frame B, convert to body frame C
+   * @param cRb rotation from body frame to camera frame
+   * @param E essential matrix E in camera frame C
+   */
+  friend EssentialMatrix operator*(const Rot3& cRb, const EssentialMatrix& E) {
+    Rot3  c1Rc2 = E.aRb_.conjugate(cRb);
+    Sphere2 c1Tc2 = cRb * E.aTb_;
+    return EssentialMatrix(c1Rc2, c1Tc2);
+  }
+
   /// epipolar error, algebraic
   double error(const Vector& vA, const Vector& vB, //
       boost::optional<Matrix&> H = boost::none) const {
diff --git a/gtsam/geometry/tests/testEssentialMatrix.cpp b/gtsam/geometry/tests/testEssentialMatrix.cpp
index 1901f3fb5..69f5ec4e7 100644
--- a/gtsam/geometry/tests/testEssentialMatrix.cpp
+++ b/gtsam/geometry/tests/testEssentialMatrix.cpp
@@ -66,19 +66,6 @@ TEST (EssentialMatrix, transform_to) {
 
 //*************************************************************************
 
-/**
- * Given essential matrix E in camera frame B, convert to body frame C
- * @param cRb rotation from body frame to camera frame
- * @param E essential matrix E in camera frame C
- */
-EssentialMatrix operator*(const Rot3& cRb, const EssentialMatrix& E) {
-  Rot3 b1Rb2 = E.rotation();
-  Sphere2 b1Tb2 = E.direction();
-  Rot3  c1Rc2 = b1Rb2.conjugate(cRb);
-  Sphere2 c1Tc2 = cRb * b1Tb2;
-  return EssentialMatrix(c1Rc2, c1Tc2);
-}
-
 TEST (EssentialMatrix, rotate) {
   // Suppose the essential matrix is specified in a body coordinate frame B
   // which is rotated with respect to the camera frame C, via rotation bRc.