diff --git a/gtsam/geometry/Line3.cpp b/gtsam/geometry/Line3.cpp
index e3b4841e0..747a58d2f 100644
--- a/gtsam/geometry/Line3.cpp
+++ b/gtsam/geometry/Line3.cpp
@@ -91,30 +91,4 @@ Point3 Line3::point(double distance) const {
   return rotated_center + distance * R_.r3();
 }
 
-Line3 transformTo(const Pose3 &wTc, const Line3 &wL,
-                  OptionalJacobian<4, 6> Dpose, OptionalJacobian<4, 4> Dline) {
-  Rot3 wRc = wTc.rotation();
-  Rot3 cRw = wRc.inverse();
-  Rot3 cRl = cRw * wL.R_;
-
-  Vector2 w_ab;
-  Vector3 t = ((wL.R_).transpose() * wTc.translation());
-  Vector2 c_ab(wL.a_ - t[0], wL.b_ - t[1]);
-
-  if (Dpose) {
-    Matrix3 lRc = (cRl.matrix()).transpose();
-    Dpose->setZero();
-    // rotation
-    Dpose->block<2, 3>(0, 0) = -lRc.block<2, 3>(0, 0);
-    // translation
-    Dpose->block<2, 3>(2, 3) = -lRc.block<2, 3>(0, 0);
-  }
-  if (Dline) {
-    Dline->setIdentity();
-    (*Dline)(0, 3) = -t[2];
-    (*Dline)(1, 2) = t[2];
-  }
-  return Line3(cRl, c_ab[0], c_ab[1]);
-}
-
-}
\ No newline at end of file
+}  // namespace gtsam
diff --git a/gtsam/geometry/Line3.h b/gtsam/geometry/Line3.h
index f70e13ca7..6dd7bf85a 100644
--- a/gtsam/geometry/Line3.h
+++ b/gtsam/geometry/Line3.h
@@ -26,7 +26,7 @@ namespace gtsam {
  * @addtogroup geometry
  * \nosubgrouping
  */
-class Line3 {
+class GTSAM_EXPORT Line3 {
  private:
   Rot3 R_;    // Rotation of line about x and y in world frame
   double a_, b_;  // Intersection of line with the world x-y plane rotated by R_
@@ -146,7 +146,30 @@ class Line3 {
  */
 Line3 transformTo(const Pose3 &wTc, const Line3 &wL,
                   OptionalJacobian<4, 6> Dpose = boost::none,
-                  OptionalJacobian<4, 4> Dline = boost::none);
+                  OptionalJacobian<4, 4> Dline = boost::none) {
+  Rot3 wRc = wTc.rotation();
+  Rot3 cRw = wRc.inverse();
+  Rot3 cRl = cRw * wL.R_;
+
+  Vector2 w_ab;
+  Vector3 t = ((wL.R_).transpose() * wTc.translation());
+  Vector2 c_ab(wL.a_ - t[0], wL.b_ - t[1]);
+
+  if (Dpose) {
+    Matrix3 lRc = (cRl.matrix()).transpose();
+    Dpose->setZero();
+    // rotation
+    Dpose->block<2, 3>(0, 0) = -lRc.block<2, 3>(0, 0);
+    // translation
+    Dpose->block<2, 3>(2, 3) = -lRc.block<2, 3>(0, 0);
+  }
+  if (Dline) {
+    Dline->setIdentity();
+    (*Dline)(0, 3) = -t[2];
+    (*Dline)(1, 2) = t[2];
+  }
+  return Line3(cRl, c_ab[0], c_ab[1]);
+}
 
 template<>
 struct traits<Line3> : public internal::Manifold<Line3> {};