diff --git a/include/double_down/RTI.hpp b/include/double_down/RTI.hpp
index 030fcf4..0ccf647 100644
--- a/include/double_down/RTI.hpp
+++ b/include/double_down/RTI.hpp
@@ -138,7 +138,7 @@ class RayTracingInterface {
   //! \param uwv optional direction vector to be consistent across calls.
   moab::ErrorCode find_volume(const double xyz[3],
                                        moab::EntityHandle &volume,
-                                       const double *uwv = NULL);
+                                       const double *uvw = NULL);
 
   //! \brief Calculates the solid angle of a polygon, \p face, with respect to \p point.
   //! This method is adapted from "Point in Polyhedron Testing Using Spherical Polygons", Paulo Cezar
diff --git a/src/RTI.cpp b/src/RTI.cpp
index 1efbea9..b68b937 100644
--- a/src/RTI.cpp
+++ b/src/RTI.cpp
@@ -763,7 +763,7 @@ RayTracingInterface::point_in_volume(const moab::EntityHandle volume,
 moab::ErrorCode
 RayTracingInterface::find_volume(const double xyz[3],
                                    moab::EntityHandle &volume,
-                                   const double *uwv = NULL)
+                                   const double *uvw = NULL)
 {
   moab::ErrorCode rval;
   rval = moab::find_volume(xyz,volume,uvw);