diff --git a/maths b/maths
index 534fc8a0..90f1c5f6 160000
--- a/maths
+++ b/maths
@@ -1 +1 @@
-Subproject commit 534fc8a07ab12374c0befcf280878f265b3b0203
+Subproject commit 90f1c5f6a85af3099b8c5521e2a171525e29a789
diff --git a/mplot/NavMesh.h b/mplot/NavMesh.h
index 33951c78..8ee81e9e 100644
--- a/mplot/NavMesh.h
+++ b/mplot/NavMesh.h
@@ -114,6 +114,13 @@ namespace mplot
          */
         sm::vec<float> tn0 = {};
 
+        /*!
+         * Stabilisation flag: if true, no rotation is applied when moving over a triangle boundary
+         * in NavMesh::compute_mesh_movement. If false, then a rotation about the triangle boundary
+         * is made.
+         */
+        bool stabilised = false;
+
         /*!
          * Return index of this->vertex that is closest to scene_coord. Can use vertexidx_to_indices
          * to find the indices into vertexPositions and vertexNormals that this index in the
@@ -1297,8 +1304,9 @@ namespace mplot
                         if (flags.test (cmm_fl::vertex_crossing)) { cd.tri_edge = this->tn0.cross (_tn); }
 
                         // Compute the reorientation due to the requested movement.
-                        // Rotate by the angle between the normals. I think this is constrained to be <= pi
-                        float rotn_angle = this->tn0.angle (_tn, cd.tri_edge);
+                        float rotn_angle = 0.0f;
+                        // Rotate by the angle between the normals (if stabilised is false). I think this is constrained to be <= pi
+                        if (stabilised == false) { this->tn0.angle (_tn, cd.tri_edge); }
                         // If tn0 and _tn are identical, then rotn_angle will be NaN, but in that case we want no rotation
                         if (std::isnan (rotn_angle)) { rotn_angle = 0.0f; }
                         sm::mat44<float> reorient_model; // reorientation transformation in sf